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TOMOYO Linux Cross Reference
Linux/fs/ext4/ext4.h

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  1 /*
  2  *  ext4.h
  3  *
  4  * Copyright (C) 1992, 1993, 1994, 1995
  5  * Remy Card (card@masi.ibp.fr)
  6  * Laboratoire MASI - Institut Blaise Pascal
  7  * Universite Pierre et Marie Curie (Paris VI)
  8  *
  9  *  from
 10  *
 11  *  linux/include/linux/minix_fs.h
 12  *
 13  *  Copyright (C) 1991, 1992  Linus Torvalds
 14  */
 15 
 16 #ifndef _EXT4_H
 17 #define _EXT4_H
 18 
 19 #include <linux/types.h>
 20 #include <linux/blkdev.h>
 21 #include <linux/magic.h>
 22 #include <linux/jbd2.h>
 23 #include <linux/quota.h>
 24 #include <linux/rwsem.h>
 25 #include <linux/rbtree.h>
 26 #include <linux/seqlock.h>
 27 #include <linux/mutex.h>
 28 #include <linux/timer.h>
 29 #include <linux/wait.h>
 30 #include <linux/blockgroup_lock.h>
 31 #include <linux/percpu_counter.h>
 32 #include <crypto/hash.h>
 33 #ifdef __KERNEL__
 34 #include <linux/compat.h>
 35 #endif
 36 
 37 /*
 38  * The fourth extended filesystem constants/structures
 39  */
 40 
 41 /*
 42  * Define EXT4FS_DEBUG to produce debug messages
 43  */
 44 #undef EXT4FS_DEBUG
 45 
 46 /*
 47  * Debug code
 48  */
 49 #ifdef EXT4FS_DEBUG
 50 #define ext4_debug(f, a...)                                             \
 51         do {                                                            \
 52                 printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",        \
 53                         __FILE__, __LINE__, __func__);                  \
 54                 printk(KERN_DEBUG f, ## a);                             \
 55         } while (0)
 56 #else
 57 #define ext4_debug(fmt, ...)    no_printk(fmt, ##__VA_ARGS__)
 58 #endif
 59 
 60 /*
 61  * Turn on EXT_DEBUG to get lots of info about extents operations.
 62  */
 63 #define EXT_DEBUG__
 64 #ifdef EXT_DEBUG
 65 #define ext_debug(fmt, ...)     printk(fmt, ##__VA_ARGS__)
 66 #else
 67 #define ext_debug(fmt, ...)     no_printk(fmt, ##__VA_ARGS__)
 68 #endif
 69 
 70 #define EXT4_ERROR_INODE(inode, fmt, a...) \
 71         ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
 72 
 73 #define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)                 \
 74         ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
 75 
 76 #define EXT4_ERROR_FILE(file, block, fmt, a...)                         \
 77         ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
 78 
 79 /* data type for block offset of block group */
 80 typedef int ext4_grpblk_t;
 81 
 82 /* data type for filesystem-wide blocks number */
 83 typedef unsigned long long ext4_fsblk_t;
 84 
 85 /* data type for file logical block number */
 86 typedef __u32 ext4_lblk_t;
 87 
 88 /* data type for block group number */
 89 typedef unsigned int ext4_group_t;
 90 
 91 /*
 92  * Flags used in mballoc's allocation_context flags field.
 93  *
 94  * Also used to show what's going on for debugging purposes when the
 95  * flag field is exported via the traceport interface
 96  */
 97 
 98 /* prefer goal again. length */
 99 #define EXT4_MB_HINT_MERGE              0x0001
100 /* blocks already reserved */
101 #define EXT4_MB_HINT_RESERVED           0x0002
102 /* metadata is being allocated */
103 #define EXT4_MB_HINT_METADATA           0x0004
104 /* first blocks in the file */
105 #define EXT4_MB_HINT_FIRST              0x0008
106 /* search for the best chunk */
107 #define EXT4_MB_HINT_BEST               0x0010
108 /* data is being allocated */
109 #define EXT4_MB_HINT_DATA               0x0020
110 /* don't preallocate (for tails) */
111 #define EXT4_MB_HINT_NOPREALLOC         0x0040
112 /* allocate for locality group */
113 #define EXT4_MB_HINT_GROUP_ALLOC        0x0080
114 /* allocate goal blocks or none */
115 #define EXT4_MB_HINT_GOAL_ONLY          0x0100
116 /* goal is meaningful */
117 #define EXT4_MB_HINT_TRY_GOAL           0x0200
118 /* blocks already pre-reserved by delayed allocation */
119 #define EXT4_MB_DELALLOC_RESERVED       0x0400
120 /* We are doing stream allocation */
121 #define EXT4_MB_STREAM_ALLOC            0x0800
122 /* Use reserved root blocks if needed */
123 #define EXT4_MB_USE_ROOT_BLOCKS         0x1000
124 
125 struct ext4_allocation_request {
126         /* target inode for block we're allocating */
127         struct inode *inode;
128         /* how many blocks we want to allocate */
129         unsigned int len;
130         /* logical block in target inode */
131         ext4_lblk_t logical;
132         /* the closest logical allocated block to the left */
133         ext4_lblk_t lleft;
134         /* the closest logical allocated block to the right */
135         ext4_lblk_t lright;
136         /* phys. target (a hint) */
137         ext4_fsblk_t goal;
138         /* phys. block for the closest logical allocated block to the left */
139         ext4_fsblk_t pleft;
140         /* phys. block for the closest logical allocated block to the right */
141         ext4_fsblk_t pright;
142         /* flags. see above EXT4_MB_HINT_* */
143         unsigned int flags;
144 };
145 
146 /*
147  * Logical to physical block mapping, used by ext4_map_blocks()
148  *
149  * This structure is used to pass requests into ext4_map_blocks() as
150  * well as to store the information returned by ext4_map_blocks().  It
151  * takes less room on the stack than a struct buffer_head.
152  */
153 #define EXT4_MAP_NEW            (1 << BH_New)
154 #define EXT4_MAP_MAPPED         (1 << BH_Mapped)
155 #define EXT4_MAP_UNWRITTEN      (1 << BH_Unwritten)
156 #define EXT4_MAP_BOUNDARY       (1 << BH_Boundary)
157 #define EXT4_MAP_UNINIT         (1 << BH_Uninit)
158 /* Sometimes (in the bigalloc case, from ext4_da_get_block_prep) the caller of
159  * ext4_map_blocks wants to know whether or not the underlying cluster has
160  * already been accounted for. EXT4_MAP_FROM_CLUSTER conveys to the caller that
161  * the requested mapping was from previously mapped (or delayed allocated)
162  * cluster. We use BH_AllocFromCluster only for this flag. BH_AllocFromCluster
163  * should never appear on buffer_head's state flags.
164  */
165 #define EXT4_MAP_FROM_CLUSTER   (1 << BH_AllocFromCluster)
166 #define EXT4_MAP_FLAGS          (EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
167                                  EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
168                                  EXT4_MAP_UNINIT | EXT4_MAP_FROM_CLUSTER)
169 
170 struct ext4_map_blocks {
171         ext4_fsblk_t m_pblk;
172         ext4_lblk_t m_lblk;
173         unsigned int m_len;
174         unsigned int m_flags;
175 };
176 
177 /*
178  * For delayed allocation tracking
179  */
180 struct mpage_da_data {
181         struct inode *inode;
182         sector_t b_blocknr;             /* start block number of extent */
183         size_t b_size;                  /* size of extent */
184         unsigned long b_state;          /* state of the extent */
185         unsigned long first_page, next_page;    /* extent of pages */
186         struct writeback_control *wbc;
187         int io_done;
188         int pages_written;
189         int retval;
190 };
191 
192 /*
193  * Flags for ext4_io_end->flags
194  */
195 #define EXT4_IO_END_UNWRITTEN   0x0001
196 #define EXT4_IO_END_ERROR       0x0002
197 #define EXT4_IO_END_QUEUED      0x0004
198 #define EXT4_IO_END_DIRECT      0x0008
199 
200 struct ext4_io_page {
201         struct page     *p_page;
202         atomic_t        p_count;
203 };
204 
205 #define MAX_IO_PAGES 128
206 
207 /*
208  * For converting uninitialized extents on a work queue.
209  *
210  * 'page' is only used from the writepage() path; 'pages' is only used for
211  * buffered writes; they are used to keep page references until conversion
212  * takes place.  For AIO/DIO, neither field is filled in.
213  */
214 typedef struct ext4_io_end {
215         struct list_head        list;           /* per-file finished IO list */
216         struct inode            *inode;         /* file being written to */
217         unsigned int            flag;           /* unwritten or not */
218         struct page             *page;          /* for writepage() path */
219         loff_t                  offset;         /* offset in the file */
220         ssize_t                 size;           /* size of the extent */
221         struct work_struct      work;           /* data work queue */
222         struct kiocb            *iocb;          /* iocb struct for AIO */
223         int                     result;         /* error value for AIO */
224         int                     num_io_pages;   /* for writepages() */
225         struct ext4_io_page     *pages[MAX_IO_PAGES]; /* for writepages() */
226 } ext4_io_end_t;
227 
228 struct ext4_io_submit {
229         int                     io_op;
230         struct bio              *io_bio;
231         ext4_io_end_t           *io_end;
232         struct ext4_io_page     *io_page;
233         sector_t                io_next_block;
234 };
235 
236 /*
237  * Special inodes numbers
238  */
239 #define EXT4_BAD_INO             1      /* Bad blocks inode */
240 #define EXT4_ROOT_INO            2      /* Root inode */
241 #define EXT4_USR_QUOTA_INO       3      /* User quota inode */
242 #define EXT4_GRP_QUOTA_INO       4      /* Group quota inode */
243 #define EXT4_BOOT_LOADER_INO     5      /* Boot loader inode */
244 #define EXT4_UNDEL_DIR_INO       6      /* Undelete directory inode */
245 #define EXT4_RESIZE_INO          7      /* Reserved group descriptors inode */
246 #define EXT4_JOURNAL_INO         8      /* Journal inode */
247 
248 /* First non-reserved inode for old ext4 filesystems */
249 #define EXT4_GOOD_OLD_FIRST_INO 11
250 
251 /*
252  * Maximal count of links to a file
253  */
254 #define EXT4_LINK_MAX           65000
255 
256 /*
257  * Macro-instructions used to manage several block sizes
258  */
259 #define EXT4_MIN_BLOCK_SIZE             1024
260 #define EXT4_MAX_BLOCK_SIZE             65536
261 #define EXT4_MIN_BLOCK_LOG_SIZE         10
262 #define EXT4_MAX_BLOCK_LOG_SIZE         16
263 #ifdef __KERNEL__
264 # define EXT4_BLOCK_SIZE(s)             ((s)->s_blocksize)
265 #else
266 # define EXT4_BLOCK_SIZE(s)             (EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
267 #endif
268 #define EXT4_ADDR_PER_BLOCK(s)          (EXT4_BLOCK_SIZE(s) / sizeof(__u32))
269 #define EXT4_CLUSTER_SIZE(s)            (EXT4_BLOCK_SIZE(s) << \
270                                          EXT4_SB(s)->s_cluster_bits)
271 #ifdef __KERNEL__
272 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_blocksize_bits)
273 # define EXT4_CLUSTER_BITS(s)           (EXT4_SB(s)->s_cluster_bits)
274 #else
275 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_log_block_size + 10)
276 #endif
277 #ifdef __KERNEL__
278 #define EXT4_ADDR_PER_BLOCK_BITS(s)     (EXT4_SB(s)->s_addr_per_block_bits)
279 #define EXT4_INODE_SIZE(s)              (EXT4_SB(s)->s_inode_size)
280 #define EXT4_FIRST_INO(s)               (EXT4_SB(s)->s_first_ino)
281 #else
282 #define EXT4_INODE_SIZE(s)      (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
283                                  EXT4_GOOD_OLD_INODE_SIZE : \
284                                  (s)->s_inode_size)
285 #define EXT4_FIRST_INO(s)       (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
286                                  EXT4_GOOD_OLD_FIRST_INO : \
287                                  (s)->s_first_ino)
288 #endif
289 #define EXT4_BLOCK_ALIGN(size, blkbits)         ALIGN((size), (1 << (blkbits)))
290 
291 /* Translate a block number to a cluster number */
292 #define EXT4_B2C(sbi, blk)      ((blk) >> (sbi)->s_cluster_bits)
293 /* Translate a cluster number to a block number */
294 #define EXT4_C2B(sbi, cluster)  ((cluster) << (sbi)->s_cluster_bits)
295 /* Translate # of blks to # of clusters */
296 #define EXT4_NUM_B2C(sbi, blks) (((blks) + (sbi)->s_cluster_ratio - 1) >> \
297                                  (sbi)->s_cluster_bits)
298 
299 /*
300  * Structure of a blocks group descriptor
301  */
302 struct ext4_group_desc
303 {
304         __le32  bg_block_bitmap_lo;     /* Blocks bitmap block */
305         __le32  bg_inode_bitmap_lo;     /* Inodes bitmap block */
306         __le32  bg_inode_table_lo;      /* Inodes table block */
307         __le16  bg_free_blocks_count_lo;/* Free blocks count */
308         __le16  bg_free_inodes_count_lo;/* Free inodes count */
309         __le16  bg_used_dirs_count_lo;  /* Directories count */
310         __le16  bg_flags;               /* EXT4_BG_flags (INODE_UNINIT, etc) */
311         __le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
312         __le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
313         __le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
314         __le16  bg_itable_unused_lo;    /* Unused inodes count */
315         __le16  bg_checksum;            /* crc16(sb_uuid+group+desc) */
316         __le32  bg_block_bitmap_hi;     /* Blocks bitmap block MSB */
317         __le32  bg_inode_bitmap_hi;     /* Inodes bitmap block MSB */
318         __le32  bg_inode_table_hi;      /* Inodes table block MSB */
319         __le16  bg_free_blocks_count_hi;/* Free blocks count MSB */
320         __le16  bg_free_inodes_count_hi;/* Free inodes count MSB */
321         __le16  bg_used_dirs_count_hi;  /* Directories count MSB */
322         __le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
323         __le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
324         __le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
325         __le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
326         __u32   bg_reserved;
327 };
328 
329 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END        \
330         (offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
331          sizeof(__le16))
332 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END        \
333         (offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
334          sizeof(__le16))
335 
336 /*
337  * Structure of a flex block group info
338  */
339 
340 struct flex_groups {
341         atomic64_t      free_clusters;
342         atomic_t        free_inodes;
343         atomic_t        used_dirs;
344 };
345 
346 #define EXT4_BG_INODE_UNINIT    0x0001 /* Inode table/bitmap not in use */
347 #define EXT4_BG_BLOCK_UNINIT    0x0002 /* Block bitmap not in use */
348 #define EXT4_BG_INODE_ZEROED    0x0004 /* On-disk itable initialized to zero */
349 
350 /*
351  * Macro-instructions used to manage group descriptors
352  */
353 #define EXT4_MIN_DESC_SIZE              32
354 #define EXT4_MIN_DESC_SIZE_64BIT        64
355 #define EXT4_MAX_DESC_SIZE              EXT4_MIN_BLOCK_SIZE
356 #define EXT4_DESC_SIZE(s)               (EXT4_SB(s)->s_desc_size)
357 #ifdef __KERNEL__
358 # define EXT4_BLOCKS_PER_GROUP(s)       (EXT4_SB(s)->s_blocks_per_group)
359 # define EXT4_CLUSTERS_PER_GROUP(s)     (EXT4_SB(s)->s_clusters_per_group)
360 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_SB(s)->s_desc_per_block)
361 # define EXT4_INODES_PER_GROUP(s)       (EXT4_SB(s)->s_inodes_per_group)
362 # define EXT4_DESC_PER_BLOCK_BITS(s)    (EXT4_SB(s)->s_desc_per_block_bits)
363 #else
364 # define EXT4_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
365 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
366 # define EXT4_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
367 #endif
368 
369 /*
370  * Constants relative to the data blocks
371  */
372 #define EXT4_NDIR_BLOCKS                12
373 #define EXT4_IND_BLOCK                  EXT4_NDIR_BLOCKS
374 #define EXT4_DIND_BLOCK                 (EXT4_IND_BLOCK + 1)
375 #define EXT4_TIND_BLOCK                 (EXT4_DIND_BLOCK + 1)
376 #define EXT4_N_BLOCKS                   (EXT4_TIND_BLOCK + 1)
377 
378 /*
379  * Inode flags
380  */
381 #define EXT4_SECRM_FL                   0x00000001 /* Secure deletion */
382 #define EXT4_UNRM_FL                    0x00000002 /* Undelete */
383 #define EXT4_COMPR_FL                   0x00000004 /* Compress file */
384 #define EXT4_SYNC_FL                    0x00000008 /* Synchronous updates */
385 #define EXT4_IMMUTABLE_FL               0x00000010 /* Immutable file */
386 #define EXT4_APPEND_FL                  0x00000020 /* writes to file may only append */
387 #define EXT4_NODUMP_FL                  0x00000040 /* do not dump file */
388 #define EXT4_NOATIME_FL                 0x00000080 /* do not update atime */
389 /* Reserved for compression usage... */
390 #define EXT4_DIRTY_FL                   0x00000100
391 #define EXT4_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
392 #define EXT4_NOCOMPR_FL                 0x00000400 /* Don't compress */
393 #define EXT4_ECOMPR_FL                  0x00000800 /* Compression error */
394 /* End compression flags --- maybe not all used */
395 #define EXT4_INDEX_FL                   0x00001000 /* hash-indexed directory */
396 #define EXT4_IMAGIC_FL                  0x00002000 /* AFS directory */
397 #define EXT4_JOURNAL_DATA_FL            0x00004000 /* file data should be journaled */
398 #define EXT4_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
399 #define EXT4_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
400 #define EXT4_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
401 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
402 #define EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
403 #define EXT4_EA_INODE_FL                0x00200000 /* Inode used for large EA */
404 #define EXT4_EOFBLOCKS_FL               0x00400000 /* Blocks allocated beyond EOF */
405 #define EXT4_INLINE_DATA_FL             0x10000000 /* Inode has inline data. */
406 #define EXT4_RESERVED_FL                0x80000000 /* reserved for ext4 lib */
407 
408 #define EXT4_FL_USER_VISIBLE            0x004BDFFF /* User visible flags */
409 #define EXT4_FL_USER_MODIFIABLE         0x004B80FF /* User modifiable flags */
410 
411 /* Flags that should be inherited by new inodes from their parent. */
412 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
413                            EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
414                            EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
415                            EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
416 
417 /* Flags that are appropriate for regular files (all but dir-specific ones). */
418 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
419 
420 /* Flags that are appropriate for non-directories/regular files. */
421 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
422 
423 /* Mask out flags that are inappropriate for the given type of inode. */
424 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
425 {
426         if (S_ISDIR(mode))
427                 return flags;
428         else if (S_ISREG(mode))
429                 return flags & EXT4_REG_FLMASK;
430         else
431                 return flags & EXT4_OTHER_FLMASK;
432 }
433 
434 /*
435  * Inode flags used for atomic set/get
436  */
437 enum {
438         EXT4_INODE_SECRM        = 0,    /* Secure deletion */
439         EXT4_INODE_UNRM         = 1,    /* Undelete */
440         EXT4_INODE_COMPR        = 2,    /* Compress file */
441         EXT4_INODE_SYNC         = 3,    /* Synchronous updates */
442         EXT4_INODE_IMMUTABLE    = 4,    /* Immutable file */
443         EXT4_INODE_APPEND       = 5,    /* writes to file may only append */
444         EXT4_INODE_NODUMP       = 6,    /* do not dump file */
445         EXT4_INODE_NOATIME      = 7,    /* do not update atime */
446 /* Reserved for compression usage... */
447         EXT4_INODE_DIRTY        = 8,
448         EXT4_INODE_COMPRBLK     = 9,    /* One or more compressed clusters */
449         EXT4_INODE_NOCOMPR      = 10,   /* Don't compress */
450         EXT4_INODE_ECOMPR       = 11,   /* Compression error */
451 /* End compression flags --- maybe not all used */
452         EXT4_INODE_INDEX        = 12,   /* hash-indexed directory */
453         EXT4_INODE_IMAGIC       = 13,   /* AFS directory */
454         EXT4_INODE_JOURNAL_DATA = 14,   /* file data should be journaled */
455         EXT4_INODE_NOTAIL       = 15,   /* file tail should not be merged */
456         EXT4_INODE_DIRSYNC      = 16,   /* dirsync behaviour (directories only) */
457         EXT4_INODE_TOPDIR       = 17,   /* Top of directory hierarchies*/
458         EXT4_INODE_HUGE_FILE    = 18,   /* Set to each huge file */
459         EXT4_INODE_EXTENTS      = 19,   /* Inode uses extents */
460         EXT4_INODE_EA_INODE     = 21,   /* Inode used for large EA */
461         EXT4_INODE_EOFBLOCKS    = 22,   /* Blocks allocated beyond EOF */
462         EXT4_INODE_INLINE_DATA  = 28,   /* Data in inode. */
463         EXT4_INODE_RESERVED     = 31,   /* reserved for ext4 lib */
464 };
465 
466 /*
467  * Since it's pretty easy to mix up bit numbers and hex values, we use a
468  * build-time check to make sure that EXT4_XXX_FL is consistent with respect to
469  * EXT4_INODE_XXX. If all is well, the macros will be dropped, so, it won't cost
470  * any extra space in the compiled kernel image, otherwise, the build will fail.
471  * It's important that these values are the same, since we are using
472  * EXT4_INODE_XXX to test for flag values, but EXT4_XXX_FL must be consistent
473  * with the values of FS_XXX_FL defined in include/linux/fs.h and the on-disk
474  * values found in ext2, ext3 and ext4 filesystems, and of course the values
475  * defined in e2fsprogs.
476  *
477  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
478  */
479 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
480 #define CHECK_FLAG_VALUE(FLAG) BUILD_BUG_ON(!TEST_FLAG_VALUE(FLAG))
481 
482 static inline void ext4_check_flag_values(void)
483 {
484         CHECK_FLAG_VALUE(SECRM);
485         CHECK_FLAG_VALUE(UNRM);
486         CHECK_FLAG_VALUE(COMPR);
487         CHECK_FLAG_VALUE(SYNC);
488         CHECK_FLAG_VALUE(IMMUTABLE);
489         CHECK_FLAG_VALUE(APPEND);
490         CHECK_FLAG_VALUE(NODUMP);
491         CHECK_FLAG_VALUE(NOATIME);
492         CHECK_FLAG_VALUE(DIRTY);
493         CHECK_FLAG_VALUE(COMPRBLK);
494         CHECK_FLAG_VALUE(NOCOMPR);
495         CHECK_FLAG_VALUE(ECOMPR);
496         CHECK_FLAG_VALUE(INDEX);
497         CHECK_FLAG_VALUE(IMAGIC);
498         CHECK_FLAG_VALUE(JOURNAL_DATA);
499         CHECK_FLAG_VALUE(NOTAIL);
500         CHECK_FLAG_VALUE(DIRSYNC);
501         CHECK_FLAG_VALUE(TOPDIR);
502         CHECK_FLAG_VALUE(HUGE_FILE);
503         CHECK_FLAG_VALUE(EXTENTS);
504         CHECK_FLAG_VALUE(EA_INODE);
505         CHECK_FLAG_VALUE(EOFBLOCKS);
506         CHECK_FLAG_VALUE(INLINE_DATA);
507         CHECK_FLAG_VALUE(RESERVED);
508 }
509 
510 /* Used to pass group descriptor data when online resize is done */
511 struct ext4_new_group_input {
512         __u32 group;            /* Group number for this data */
513         __u64 block_bitmap;     /* Absolute block number of block bitmap */
514         __u64 inode_bitmap;     /* Absolute block number of inode bitmap */
515         __u64 inode_table;      /* Absolute block number of inode table start */
516         __u32 blocks_count;     /* Total number of blocks in this group */
517         __u16 reserved_blocks;  /* Number of reserved blocks in this group */
518         __u16 unused;
519 };
520 
521 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
522 struct compat_ext4_new_group_input {
523         u32 group;
524         compat_u64 block_bitmap;
525         compat_u64 inode_bitmap;
526         compat_u64 inode_table;
527         u32 blocks_count;
528         u16 reserved_blocks;
529         u16 unused;
530 };
531 #endif
532 
533 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
534 struct ext4_new_group_data {
535         __u32 group;
536         __u64 block_bitmap;
537         __u64 inode_bitmap;
538         __u64 inode_table;
539         __u32 blocks_count;
540         __u16 reserved_blocks;
541         __u16 unused;
542         __u32 free_blocks_count;
543 };
544 
545 /* Indexes used to index group tables in ext4_new_group_data */
546 enum {
547         BLOCK_BITMAP = 0,       /* block bitmap */
548         INODE_BITMAP,           /* inode bitmap */
549         INODE_TABLE,            /* inode tables */
550         GROUP_TABLE_COUNT,
551 };
552 
553 /*
554  * Flags used by ext4_map_blocks()
555  */
556         /* Allocate any needed blocks and/or convert an unitialized
557            extent to be an initialized ext4 */
558 #define EXT4_GET_BLOCKS_CREATE                  0x0001
559         /* Request the creation of an unitialized extent */
560 #define EXT4_GET_BLOCKS_UNINIT_EXT              0x0002
561 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT       (EXT4_GET_BLOCKS_UNINIT_EXT|\
562                                                  EXT4_GET_BLOCKS_CREATE)
563         /* Caller is from the delayed allocation writeout path,
564            so set the magic i_delalloc_reserve_flag after taking the
565            inode allocation semaphore for */
566 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE        0x0004
567         /* caller is from the direct IO path, request to creation of an
568         unitialized extents if not allocated, split the uninitialized
569         extent if blocks has been preallocated already*/
570 #define EXT4_GET_BLOCKS_PRE_IO                  0x0008
571 #define EXT4_GET_BLOCKS_CONVERT                 0x0010
572 #define EXT4_GET_BLOCKS_IO_CREATE_EXT           (EXT4_GET_BLOCKS_PRE_IO|\
573                                          EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
574         /* Convert extent to initialized after IO complete */
575 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT          (EXT4_GET_BLOCKS_CONVERT|\
576                                          EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
577         /* Punch out blocks of an extent */
578 #define EXT4_GET_BLOCKS_PUNCH_OUT_EXT           0x0020
579         /* Don't normalize allocation size (used for fallocate) */
580 #define EXT4_GET_BLOCKS_NO_NORMALIZE            0x0040
581         /* Request will not result in inode size update (user for fallocate) */
582 #define EXT4_GET_BLOCKS_KEEP_SIZE               0x0080
583         /* Do not take i_data_sem locking in ext4_map_blocks */
584 #define EXT4_GET_BLOCKS_NO_LOCK                 0x0100
585 
586 /*
587  * Flags used by ext4_free_blocks
588  */
589 #define EXT4_FREE_BLOCKS_METADATA       0x0001
590 #define EXT4_FREE_BLOCKS_FORGET         0x0002
591 #define EXT4_FREE_BLOCKS_VALIDATED      0x0004
592 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE 0x0008
593 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER   0x0010
594 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER    0x0020
595 
596 /*
597  * Flags used by ext4_discard_partial_page_buffers
598  */
599 #define EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED   0x0001
600 
601 /*
602  * ioctl commands
603  */
604 #define EXT4_IOC_GETFLAGS               FS_IOC_GETFLAGS
605 #define EXT4_IOC_SETFLAGS               FS_IOC_SETFLAGS
606 #define EXT4_IOC_GETVERSION             _IOR('f', 3, long)
607 #define EXT4_IOC_SETVERSION             _IOW('f', 4, long)
608 #define EXT4_IOC_GETVERSION_OLD         FS_IOC_GETVERSION
609 #define EXT4_IOC_SETVERSION_OLD         FS_IOC_SETVERSION
610 #define EXT4_IOC_GETRSVSZ               _IOR('f', 5, long)
611 #define EXT4_IOC_SETRSVSZ               _IOW('f', 6, long)
612 #define EXT4_IOC_GROUP_EXTEND           _IOW('f', 7, unsigned long)
613 #define EXT4_IOC_GROUP_ADD              _IOW('f', 8, struct ext4_new_group_input)
614 #define EXT4_IOC_MIGRATE                _IO('f', 9)
615  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
616  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
617 #define EXT4_IOC_ALLOC_DA_BLKS          _IO('f', 12)
618 #define EXT4_IOC_MOVE_EXT               _IOWR('f', 15, struct move_extent)
619 #define EXT4_IOC_RESIZE_FS              _IOW('f', 16, __u64)
620 
621 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
622 /*
623  * ioctl commands in 32 bit emulation
624  */
625 #define EXT4_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
626 #define EXT4_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
627 #define EXT4_IOC32_GETVERSION           _IOR('f', 3, int)
628 #define EXT4_IOC32_SETVERSION           _IOW('f', 4, int)
629 #define EXT4_IOC32_GETRSVSZ             _IOR('f', 5, int)
630 #define EXT4_IOC32_SETRSVSZ             _IOW('f', 6, int)
631 #define EXT4_IOC32_GROUP_EXTEND         _IOW('f', 7, unsigned int)
632 #define EXT4_IOC32_GROUP_ADD            _IOW('f', 8, struct compat_ext4_new_group_input)
633 #define EXT4_IOC32_GETVERSION_OLD       FS_IOC32_GETVERSION
634 #define EXT4_IOC32_SETVERSION_OLD       FS_IOC32_SETVERSION
635 #endif
636 
637 /* Max physical block we can address w/o extents */
638 #define EXT4_MAX_BLOCK_FILE_PHYS        0xFFFFFFFF
639 
640 /*
641  * Structure of an inode on the disk
642  */
643 struct ext4_inode {
644         __le16  i_mode;         /* File mode */
645         __le16  i_uid;          /* Low 16 bits of Owner Uid */
646         __le32  i_size_lo;      /* Size in bytes */
647         __le32  i_atime;        /* Access time */
648         __le32  i_ctime;        /* Inode Change time */
649         __le32  i_mtime;        /* Modification time */
650         __le32  i_dtime;        /* Deletion Time */
651         __le16  i_gid;          /* Low 16 bits of Group Id */
652         __le16  i_links_count;  /* Links count */
653         __le32  i_blocks_lo;    /* Blocks count */
654         __le32  i_flags;        /* File flags */
655         union {
656                 struct {
657                         __le32  l_i_version;
658                 } linux1;
659                 struct {
660                         __u32  h_i_translator;
661                 } hurd1;
662                 struct {
663                         __u32  m_i_reserved1;
664                 } masix1;
665         } osd1;                         /* OS dependent 1 */
666         __le32  i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
667         __le32  i_generation;   /* File version (for NFS) */
668         __le32  i_file_acl_lo;  /* File ACL */
669         __le32  i_size_high;
670         __le32  i_obso_faddr;   /* Obsoleted fragment address */
671         union {
672                 struct {
673                         __le16  l_i_blocks_high; /* were l_i_reserved1 */
674                         __le16  l_i_file_acl_high;
675                         __le16  l_i_uid_high;   /* these 2 fields */
676                         __le16  l_i_gid_high;   /* were reserved2[0] */
677                         __le16  l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
678                         __le16  l_i_reserved;
679                 } linux2;
680                 struct {
681                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
682                         __u16   h_i_mode_high;
683                         __u16   h_i_uid_high;
684                         __u16   h_i_gid_high;
685                         __u32   h_i_author;
686                 } hurd2;
687                 struct {
688                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
689                         __le16  m_i_file_acl_high;
690                         __u32   m_i_reserved2[2];
691                 } masix2;
692         } osd2;                         /* OS dependent 2 */
693         __le16  i_extra_isize;
694         __le16  i_checksum_hi;  /* crc32c(uuid+inum+inode) BE */
695         __le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
696         __le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
697         __le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
698         __le32  i_crtime;       /* File Creation time */
699         __le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
700         __le32  i_version_hi;   /* high 32 bits for 64-bit version */
701 };
702 
703 struct move_extent {
704         __u32 reserved;         /* should be zero */
705         __u32 donor_fd;         /* donor file descriptor */
706         __u64 orig_start;       /* logical start offset in block for orig */
707         __u64 donor_start;      /* logical start offset in block for donor */
708         __u64 len;              /* block length to be moved */
709         __u64 moved_len;        /* moved block length */
710 };
711 
712 #define EXT4_EPOCH_BITS 2
713 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
714 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
715 
716 /*
717  * Extended fields will fit into an inode if the filesystem was formatted
718  * with large inodes (-I 256 or larger) and there are not currently any EAs
719  * consuming all of the available space. For new inodes we always reserve
720  * enough space for the kernel's known extended fields, but for inodes
721  * created with an old kernel this might not have been the case. None of
722  * the extended inode fields is critical for correct filesystem operation.
723  * This macro checks if a certain field fits in the inode. Note that
724  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
725  */
726 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)   \
727         ((offsetof(typeof(*ext4_inode), field) +        \
728           sizeof((ext4_inode)->field))                  \
729         <= (EXT4_GOOD_OLD_INODE_SIZE +                  \
730             (einode)->i_extra_isize))                   \
731 
732 static inline __le32 ext4_encode_extra_time(struct timespec *time)
733 {
734        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
735                            (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
736                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
737 }
738 
739 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
740 {
741        if (sizeof(time->tv_sec) > 4)
742                time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
743                                << 32;
744        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
745 }
746 
747 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)                          \
748 do {                                                                           \
749         (raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);               \
750         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
751                 (raw_inode)->xtime ## _extra =                                 \
752                                 ext4_encode_extra_time(&(inode)->xtime);       \
753 } while (0)
754 
755 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)                        \
756 do {                                                                           \
757         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
758                 (raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
759         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
760                 (raw_inode)->xtime ## _extra =                                 \
761                                 ext4_encode_extra_time(&(einode)->xtime);      \
762 } while (0)
763 
764 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)                          \
765 do {                                                                           \
766         (inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
767         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
768                 ext4_decode_extra_time(&(inode)->xtime,                        \
769                                        raw_inode->xtime ## _extra);            \
770         else                                                                   \
771                 (inode)->xtime.tv_nsec = 0;                                    \
772 } while (0)
773 
774 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)                        \
775 do {                                                                           \
776         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
777                 (einode)->xtime.tv_sec =                                       \
778                         (signed)le32_to_cpu((raw_inode)->xtime);               \
779         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
780                 ext4_decode_extra_time(&(einode)->xtime,                       \
781                                        raw_inode->xtime ## _extra);            \
782         else                                                                   \
783                 (einode)->xtime.tv_nsec = 0;                                   \
784 } while (0)
785 
786 #define i_disk_version osd1.linux1.l_i_version
787 
788 #if defined(__KERNEL__) || defined(__linux__)
789 #define i_reserved1     osd1.linux1.l_i_reserved1
790 #define i_file_acl_high osd2.linux2.l_i_file_acl_high
791 #define i_blocks_high   osd2.linux2.l_i_blocks_high
792 #define i_uid_low       i_uid
793 #define i_gid_low       i_gid
794 #define i_uid_high      osd2.linux2.l_i_uid_high
795 #define i_gid_high      osd2.linux2.l_i_gid_high
796 #define i_checksum_lo   osd2.linux2.l_i_checksum_lo
797 
798 #elif defined(__GNU__)
799 
800 #define i_translator    osd1.hurd1.h_i_translator
801 #define i_uid_high      osd2.hurd2.h_i_uid_high
802 #define i_gid_high      osd2.hurd2.h_i_gid_high
803 #define i_author        osd2.hurd2.h_i_author
804 
805 #elif defined(__masix__)
806 
807 #define i_reserved1     osd1.masix1.m_i_reserved1
808 #define i_file_acl_high osd2.masix2.m_i_file_acl_high
809 #define i_reserved2     osd2.masix2.m_i_reserved2
810 
811 #endif /* defined(__KERNEL__) || defined(__linux__) */
812 
813 /*
814  * storage for cached extent
815  * If ec_len == 0, then the cache is invalid.
816  * If ec_start == 0, then the cache represents a gap (null mapping)
817  */
818 struct ext4_ext_cache {
819         ext4_fsblk_t    ec_start;
820         ext4_lblk_t     ec_block;
821         __u32           ec_len; /* must be 32bit to return holes */
822 };
823 
824 #include "extents_status.h"
825 
826 /*
827  * fourth extended file system inode data in memory
828  */
829 struct ext4_inode_info {
830         __le32  i_data[15];     /* unconverted */
831         __u32   i_dtime;
832         ext4_fsblk_t    i_file_acl;
833 
834         /*
835          * i_block_group is the number of the block group which contains
836          * this file's inode.  Constant across the lifetime of the inode,
837          * it is ued for making block allocation decisions - we try to
838          * place a file's data blocks near its inode block, and new inodes
839          * near to their parent directory's inode.
840          */
841         ext4_group_t    i_block_group;
842         ext4_lblk_t     i_dir_start_lookup;
843 #if (BITS_PER_LONG < 64)
844         unsigned long   i_state_flags;          /* Dynamic state flags */
845 #endif
846         unsigned long   i_flags;
847 
848         /*
849          * Extended attributes can be read independently of the main file
850          * data. Taking i_mutex even when reading would cause contention
851          * between readers of EAs and writers of regular file data, so
852          * instead we synchronize on xattr_sem when reading or changing
853          * EAs.
854          */
855         struct rw_semaphore xattr_sem;
856 
857         struct list_head i_orphan;      /* unlinked but open inodes */
858 
859         /*
860          * i_disksize keeps track of what the inode size is ON DISK, not
861          * in memory.  During truncate, i_size is set to the new size by
862          * the VFS prior to calling ext4_truncate(), but the filesystem won't
863          * set i_disksize to 0 until the truncate is actually under way.
864          *
865          * The intent is that i_disksize always represents the blocks which
866          * are used by this file.  This allows recovery to restart truncate
867          * on orphans if we crash during truncate.  We actually write i_disksize
868          * into the on-disk inode when writing inodes out, instead of i_size.
869          *
870          * The only time when i_disksize and i_size may be different is when
871          * a truncate is in progress.  The only things which change i_disksize
872          * are ext4_get_block (growth) and ext4_truncate (shrinkth).
873          */
874         loff_t  i_disksize;
875 
876         /*
877          * i_data_sem is for serialising ext4_truncate() against
878          * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
879          * data tree are chopped off during truncate. We can't do that in
880          * ext4 because whenever we perform intermediate commits during
881          * truncate, the inode and all the metadata blocks *must* be in a
882          * consistent state which allows truncation of the orphans to restart
883          * during recovery.  Hence we must fix the get_block-vs-truncate race
884          * by other means, so we have i_data_sem.
885          */
886         struct rw_semaphore i_data_sem;
887         struct inode vfs_inode;
888         struct jbd2_inode *jinode;
889 
890         struct ext4_ext_cache i_cached_extent;
891         /*
892          * File creation time. Its function is same as that of
893          * struct timespec i_{a,c,m}time in the generic inode.
894          */
895         struct timespec i_crtime;
896 
897         /* mballoc */
898         struct list_head i_prealloc_list;
899         spinlock_t i_prealloc_lock;
900 
901         /* extents status tree */
902         struct ext4_es_tree i_es_tree;
903         rwlock_t i_es_lock;
904 
905         /* ialloc */
906         ext4_group_t    i_last_alloc_group;
907 
908         /* allocation reservation info for delalloc */
909         /* In case of bigalloc, these refer to clusters rather than blocks */
910         unsigned int i_reserved_data_blocks;
911         unsigned int i_reserved_meta_blocks;
912         unsigned int i_allocated_meta_blocks;
913         ext4_lblk_t i_da_metadata_calc_last_lblock;
914         int i_da_metadata_calc_len;
915 
916         /* on-disk additional length */
917         __u16 i_extra_isize;
918 
919         /* Indicate the inline data space. */
920         u16 i_inline_off;
921         u16 i_inline_size;
922 
923 #ifdef CONFIG_QUOTA
924         /* quota space reservation, managed internally by quota code */
925         qsize_t i_reserved_quota;
926 #endif
927 
928         /* completed IOs that might need unwritten extents handling */
929         struct list_head i_completed_io_list;
930         spinlock_t i_completed_io_lock;
931         atomic_t i_ioend_count; /* Number of outstanding io_end structs */
932         atomic_t i_unwritten; /* Nr. of inflight conversions pending */
933 
934         spinlock_t i_block_reservation_lock;
935 
936         /*
937          * Transactions that contain inode's metadata needed to complete
938          * fsync and fdatasync, respectively.
939          */
940         tid_t i_sync_tid;
941         tid_t i_datasync_tid;
942 
943         /* Precomputed uuid+inum+igen checksum for seeding inode checksums */
944         __u32 i_csum_seed;
945 };
946 
947 /*
948  * File system states
949  */
950 #define EXT4_VALID_FS                   0x0001  /* Unmounted cleanly */
951 #define EXT4_ERROR_FS                   0x0002  /* Errors detected */
952 #define EXT4_ORPHAN_FS                  0x0004  /* Orphans being recovered */
953 
954 /*
955  * Misc. filesystem flags
956  */
957 #define EXT2_FLAGS_SIGNED_HASH          0x0001  /* Signed dirhash in use */
958 #define EXT2_FLAGS_UNSIGNED_HASH        0x0002  /* Unsigned dirhash in use */
959 #define EXT2_FLAGS_TEST_FILESYS         0x0004  /* to test development code */
960 
961 /*
962  * Mount flags
963  */
964 #define EXT4_MOUNT_GRPID                0x00004 /* Create files with directory's group */
965 #define EXT4_MOUNT_DEBUG                0x00008 /* Some debugging messages */
966 #define EXT4_MOUNT_ERRORS_CONT          0x00010 /* Continue on errors */
967 #define EXT4_MOUNT_ERRORS_RO            0x00020 /* Remount fs ro on errors */
968 #define EXT4_MOUNT_ERRORS_PANIC         0x00040 /* Panic on errors */
969 #define EXT4_MOUNT_ERRORS_MASK          0x00070
970 #define EXT4_MOUNT_MINIX_DF             0x00080 /* Mimics the Minix statfs */
971 #define EXT4_MOUNT_NOLOAD               0x00100 /* Don't use existing journal*/
972 #define EXT4_MOUNT_DATA_FLAGS           0x00C00 /* Mode for data writes: */
973 #define EXT4_MOUNT_JOURNAL_DATA         0x00400 /* Write data to journal */
974 #define EXT4_MOUNT_ORDERED_DATA         0x00800 /* Flush data before commit */
975 #define EXT4_MOUNT_WRITEBACK_DATA       0x00C00 /* No data ordering */
976 #define EXT4_MOUNT_UPDATE_JOURNAL       0x01000 /* Update the journal format */
977 #define EXT4_MOUNT_NO_UID32             0x02000  /* Disable 32-bit UIDs */
978 #define EXT4_MOUNT_XATTR_USER           0x04000 /* Extended user attributes */
979 #define EXT4_MOUNT_POSIX_ACL            0x08000 /* POSIX Access Control Lists */
980 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC     0x10000 /* No auto delalloc mapping */
981 #define EXT4_MOUNT_BARRIER              0x20000 /* Use block barriers */
982 #define EXT4_MOUNT_QUOTA                0x80000 /* Some quota option set */
983 #define EXT4_MOUNT_USRQUOTA             0x100000 /* "old" user quota */
984 #define EXT4_MOUNT_GRPQUOTA             0x200000 /* "old" group quota */
985 #define EXT4_MOUNT_DIOREAD_NOLOCK       0x400000 /* Enable support for dio read nolocking */
986 #define EXT4_MOUNT_JOURNAL_CHECKSUM     0x800000 /* Journal checksums */
987 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
988 #define EXT4_MOUNT_MBLK_IO_SUBMIT       0x4000000 /* multi-block io submits */
989 #define EXT4_MOUNT_DELALLOC             0x8000000 /* Delalloc support */
990 #define EXT4_MOUNT_DATA_ERR_ABORT       0x10000000 /* Abort on file data write */
991 #define EXT4_MOUNT_BLOCK_VALIDITY       0x20000000 /* Block validity checking */
992 #define EXT4_MOUNT_DISCARD              0x40000000 /* Issue DISCARD requests */
993 #define EXT4_MOUNT_INIT_INODE_TABLE     0x80000000 /* Initialize uninitialized itables */
994 
995 #define EXT4_MOUNT2_EXPLICIT_DELALLOC   0x00000001 /* User explicitly
996                                                       specified delalloc */
997 
998 #define clear_opt(sb, opt)              EXT4_SB(sb)->s_mount_opt &= \
999                                                 ~EXT4_MOUNT_##opt
1000 #define set_opt(sb, opt)                EXT4_SB(sb)->s_mount_opt |= \
1001                                                 EXT4_MOUNT_##opt
1002 #define test_opt(sb, opt)               (EXT4_SB(sb)->s_mount_opt & \
1003                                          EXT4_MOUNT_##opt)
1004 
1005 #define clear_opt2(sb, opt)             EXT4_SB(sb)->s_mount_opt2 &= \
1006                                                 ~EXT4_MOUNT2_##opt
1007 #define set_opt2(sb, opt)               EXT4_SB(sb)->s_mount_opt2 |= \
1008                                                 EXT4_MOUNT2_##opt
1009 #define test_opt2(sb, opt)              (EXT4_SB(sb)->s_mount_opt2 & \
1010                                          EXT4_MOUNT2_##opt)
1011 
1012 #define ext4_test_and_set_bit           __test_and_set_bit_le
1013 #define ext4_set_bit                    __set_bit_le
1014 #define ext4_set_bit_atomic             ext2_set_bit_atomic
1015 #define ext4_test_and_clear_bit         __test_and_clear_bit_le
1016 #define ext4_clear_bit                  __clear_bit_le
1017 #define ext4_clear_bit_atomic           ext2_clear_bit_atomic
1018 #define ext4_test_bit                   test_bit_le
1019 #define ext4_find_next_zero_bit         find_next_zero_bit_le
1020 #define ext4_find_next_bit              find_next_bit_le
1021 
1022 extern void ext4_set_bits(void *bm, int cur, int len);
1023 
1024 /*
1025  * Maximal mount counts between two filesystem checks
1026  */
1027 #define EXT4_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
1028 #define EXT4_DFL_CHECKINTERVAL          0       /* Don't use interval check */
1029 
1030 /*
1031  * Behaviour when detecting errors
1032  */
1033 #define EXT4_ERRORS_CONTINUE            1       /* Continue execution */
1034 #define EXT4_ERRORS_RO                  2       /* Remount fs read-only */
1035 #define EXT4_ERRORS_PANIC               3       /* Panic */
1036 #define EXT4_ERRORS_DEFAULT             EXT4_ERRORS_CONTINUE
1037 
1038 /* Metadata checksum algorithm codes */
1039 #define EXT4_CRC32C_CHKSUM              1
1040 
1041 /*
1042  * Structure of the super block
1043  */
1044 struct ext4_super_block {
1045 /*00*/  __le32  s_inodes_count;         /* Inodes count */
1046         __le32  s_blocks_count_lo;      /* Blocks count */
1047         __le32  s_r_blocks_count_lo;    /* Reserved blocks count */
1048         __le32  s_free_blocks_count_lo; /* Free blocks count */
1049 /*10*/  __le32  s_free_inodes_count;    /* Free inodes count */
1050         __le32  s_first_data_block;     /* First Data Block */
1051         __le32  s_log_block_size;       /* Block size */
1052         __le32  s_log_cluster_size;     /* Allocation cluster size */
1053 /*20*/  __le32  s_blocks_per_group;     /* # Blocks per group */
1054         __le32  s_clusters_per_group;   /* # Clusters per group */
1055         __le32  s_inodes_per_group;     /* # Inodes per group */
1056         __le32  s_mtime;                /* Mount time */
1057 /*30*/  __le32  s_wtime;                /* Write time */
1058         __le16  s_mnt_count;            /* Mount count */
1059         __le16  s_max_mnt_count;        /* Maximal mount count */
1060         __le16  s_magic;                /* Magic signature */
1061         __le16  s_state;                /* File system state */
1062         __le16  s_errors;               /* Behaviour when detecting errors */
1063         __le16  s_minor_rev_level;      /* minor revision level */
1064 /*40*/  __le32  s_lastcheck;            /* time of last check */
1065         __le32  s_checkinterval;        /* max. time between checks */
1066         __le32  s_creator_os;           /* OS */
1067         __le32  s_rev_level;            /* Revision level */
1068 /*50*/  __le16  s_def_resuid;           /* Default uid for reserved blocks */
1069         __le16  s_def_resgid;           /* Default gid for reserved blocks */
1070         /*
1071          * These fields are for EXT4_DYNAMIC_REV superblocks only.
1072          *
1073          * Note: the difference between the compatible feature set and
1074          * the incompatible feature set is that if there is a bit set
1075          * in the incompatible feature set that the kernel doesn't
1076          * know about, it should refuse to mount the filesystem.
1077          *
1078          * e2fsck's requirements are more strict; if it doesn't know
1079          * about a feature in either the compatible or incompatible
1080          * feature set, it must abort and not try to meddle with
1081          * things it doesn't understand...
1082          */
1083         __le32  s_first_ino;            /* First non-reserved inode */
1084         __le16  s_inode_size;           /* size of inode structure */
1085         __le16  s_block_group_nr;       /* block group # of this superblock */
1086         __le32  s_feature_compat;       /* compatible feature set */
1087 /*60*/  __le32  s_feature_incompat;     /* incompatible feature set */
1088         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
1089 /*68*/  __u8    s_uuid[16];             /* 128-bit uuid for volume */
1090 /*78*/  char    s_volume_name[16];      /* volume name */
1091 /*88*/  char    s_last_mounted[64];     /* directory where last mounted */
1092 /*C8*/  __le32  s_algorithm_usage_bitmap; /* For compression */
1093         /*
1094          * Performance hints.  Directory preallocation should only
1095          * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1096          */
1097         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
1098         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
1099         __le16  s_reserved_gdt_blocks;  /* Per group desc for online growth */
1100         /*
1101          * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1102          */
1103 /*D0*/  __u8    s_journal_uuid[16];     /* uuid of journal superblock */
1104 /*E0*/  __le32  s_journal_inum;         /* inode number of journal file */
1105         __le32  s_journal_dev;          /* device number of journal file */
1106         __le32  s_last_orphan;          /* start of list of inodes to delete */
1107         __le32  s_hash_seed[4];         /* HTREE hash seed */
1108         __u8    s_def_hash_version;     /* Default hash version to use */
1109         __u8    s_jnl_backup_type;
1110         __le16  s_desc_size;            /* size of group descriptor */
1111 /*100*/ __le32  s_default_mount_opts;
1112         __le32  s_first_meta_bg;        /* First metablock block group */
1113         __le32  s_mkfs_time;            /* When the filesystem was created */
1114         __le32  s_jnl_blocks[17];       /* Backup of the journal inode */
1115         /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1116 /*150*/ __le32  s_blocks_count_hi;      /* Blocks count */
1117         __le32  s_r_blocks_count_hi;    /* Reserved blocks count */
1118         __le32  s_free_blocks_count_hi; /* Free blocks count */
1119         __le16  s_min_extra_isize;      /* All inodes have at least # bytes */
1120         __le16  s_want_extra_isize;     /* New inodes should reserve # bytes */
1121         __le32  s_flags;                /* Miscellaneous flags */
1122         __le16  s_raid_stride;          /* RAID stride */
1123         __le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1124         __le64  s_mmp_block;            /* Block for multi-mount protection */
1125         __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1126         __u8    s_log_groups_per_flex;  /* FLEX_BG group size */
1127         __u8    s_checksum_type;        /* metadata checksum algorithm used */
1128         __le16  s_reserved_pad;
1129         __le64  s_kbytes_written;       /* nr of lifetime kilobytes written */
1130         __le32  s_snapshot_inum;        /* Inode number of active snapshot */
1131         __le32  s_snapshot_id;          /* sequential ID of active snapshot */
1132         __le64  s_snapshot_r_blocks_count; /* reserved blocks for active
1133                                               snapshot's future use */
1134         __le32  s_snapshot_list;        /* inode number of the head of the
1135                                            on-disk snapshot list */
1136 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1137         __le32  s_error_count;          /* number of fs errors */
1138         __le32  s_first_error_time;     /* first time an error happened */
1139         __le32  s_first_error_ino;      /* inode involved in first error */
1140         __le64  s_first_error_block;    /* block involved of first error */
1141         __u8    s_first_error_func[32]; /* function where the error happened */
1142         __le32  s_first_error_line;     /* line number where error happened */
1143         __le32  s_last_error_time;      /* most recent time of an error */
1144         __le32  s_last_error_ino;       /* inode involved in last error */
1145         __le32  s_last_error_line;      /* line number where error happened */
1146         __le64  s_last_error_block;     /* block involved of last error */
1147         __u8    s_last_error_func[32];  /* function where the error happened */
1148 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1149         __u8    s_mount_opts[64];
1150         __le32  s_usr_quota_inum;       /* inode for tracking user quota */
1151         __le32  s_grp_quota_inum;       /* inode for tracking group quota */
1152         __le32  s_overhead_clusters;    /* overhead blocks/clusters in fs */
1153         __le32  s_reserved[108];        /* Padding to the end of the block */
1154         __le32  s_checksum;             /* crc32c(superblock) */
1155 };
1156 
1157 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1158 
1159 #ifdef __KERNEL__
1160 
1161 /*
1162  * run-time mount flags
1163  */
1164 #define EXT4_MF_MNTDIR_SAMPLED  0x0001
1165 #define EXT4_MF_FS_ABORTED      0x0002  /* Fatal error detected */
1166 
1167 /*
1168  * fourth extended-fs super-block data in memory
1169  */
1170 struct ext4_sb_info {
1171         unsigned long s_desc_size;      /* Size of a group descriptor in bytes */
1172         unsigned long s_inodes_per_block;/* Number of inodes per block */
1173         unsigned long s_blocks_per_group;/* Number of blocks in a group */
1174         unsigned long s_clusters_per_group; /* Number of clusters in a group */
1175         unsigned long s_inodes_per_group;/* Number of inodes in a group */
1176         unsigned long s_itb_per_group;  /* Number of inode table blocks per group */
1177         unsigned long s_gdb_count;      /* Number of group descriptor blocks */
1178         unsigned long s_desc_per_block; /* Number of group descriptors per block */
1179         ext4_group_t s_groups_count;    /* Number of groups in the fs */
1180         ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1181         unsigned long s_overhead;  /* # of fs overhead clusters */
1182         unsigned int s_cluster_ratio;   /* Number of blocks per cluster */
1183         unsigned int s_cluster_bits;    /* log2 of s_cluster_ratio */
1184         loff_t s_bitmap_maxbytes;       /* max bytes for bitmap files */
1185         struct buffer_head * s_sbh;     /* Buffer containing the super block */
1186         struct ext4_super_block *s_es;  /* Pointer to the super block in the buffer */
1187         struct buffer_head **s_group_desc;
1188         unsigned int s_mount_opt;
1189         unsigned int s_mount_opt2;
1190         unsigned int s_mount_flags;
1191         unsigned int s_def_mount_opt;
1192         ext4_fsblk_t s_sb_block;
1193         kuid_t s_resuid;
1194         kgid_t s_resgid;
1195         unsigned short s_mount_state;
1196         unsigned short s_pad;
1197         int s_addr_per_block_bits;
1198         int s_desc_per_block_bits;
1199         int s_inode_size;
1200         int s_first_ino;
1201         unsigned int s_inode_readahead_blks;
1202         unsigned int s_inode_goal;
1203         spinlock_t s_next_gen_lock;
1204         u32 s_next_generation;
1205         u32 s_hash_seed[4];
1206         int s_def_hash_version;
1207         int s_hash_unsigned;    /* 3 if hash should be signed, 0 if not */
1208         struct percpu_counter s_freeclusters_counter;
1209         struct percpu_counter s_freeinodes_counter;
1210         struct percpu_counter s_dirs_counter;
1211         struct percpu_counter s_dirtyclusters_counter;
1212         struct blockgroup_lock *s_blockgroup_lock;
1213         struct proc_dir_entry *s_proc;
1214         struct kobject s_kobj;
1215         struct completion s_kobj_unregister;
1216         struct super_block *s_sb;
1217 
1218         /* Journaling */
1219         struct journal_s *s_journal;
1220         struct list_head s_orphan;
1221         struct mutex s_orphan_lock;
1222         unsigned long s_resize_flags;           /* Flags indicating if there
1223                                                    is a resizer */
1224         unsigned long s_commit_interval;
1225         u32 s_max_batch_time;
1226         u32 s_min_batch_time;
1227         struct block_device *journal_bdev;
1228 #ifdef CONFIG_QUOTA
1229         char *s_qf_names[MAXQUOTAS];            /* Names of quota files with journalled quota */
1230         int s_jquota_fmt;                       /* Format of quota to use */
1231 #endif
1232         unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1233         struct rb_root system_blks;
1234 
1235 #ifdef EXTENTS_STATS
1236         /* ext4 extents stats */
1237         unsigned long s_ext_min;
1238         unsigned long s_ext_max;
1239         unsigned long s_depth_max;
1240         spinlock_t s_ext_stats_lock;
1241         unsigned long s_ext_blocks;
1242         unsigned long s_ext_extents;
1243 #endif
1244 
1245         /* for buddy allocator */
1246         struct ext4_group_info ***s_group_info;
1247         struct inode *s_buddy_cache;
1248         spinlock_t s_md_lock;
1249         unsigned short *s_mb_offsets;
1250         unsigned int *s_mb_maxs;
1251         unsigned int s_group_info_size;
1252 
1253         /* tunables */
1254         unsigned long s_stripe;
1255         unsigned int s_mb_stream_request;
1256         unsigned int s_mb_max_to_scan;
1257         unsigned int s_mb_min_to_scan;
1258         unsigned int s_mb_stats;
1259         unsigned int s_mb_order2_reqs;
1260         unsigned int s_mb_group_prealloc;
1261         unsigned int s_max_writeback_mb_bump;
1262         unsigned int s_max_dir_size_kb;
1263         /* where last allocation was done - for stream allocation */
1264         unsigned long s_mb_last_group;
1265         unsigned long s_mb_last_start;
1266 
1267         /* stats for buddy allocator */
1268         atomic_t s_bal_reqs;    /* number of reqs with len > 1 */
1269         atomic_t s_bal_success; /* we found long enough chunks */
1270         atomic_t s_bal_allocated;       /* in blocks */
1271         atomic_t s_bal_ex_scanned;      /* total extents scanned */
1272         atomic_t s_bal_goals;   /* goal hits */
1273         atomic_t s_bal_breaks;  /* too long searches */
1274         atomic_t s_bal_2orders; /* 2^order hits */
1275         spinlock_t s_bal_lock;
1276         unsigned long s_mb_buddies_generated;
1277         unsigned long long s_mb_generation_time;
1278         atomic_t s_mb_lost_chunks;
1279         atomic_t s_mb_preallocated;
1280         atomic_t s_mb_discarded;
1281         atomic_t s_lock_busy;
1282 
1283         /* locality groups */
1284         struct ext4_locality_group __percpu *s_locality_groups;
1285 
1286         /* for write statistics */
1287         unsigned long s_sectors_written_start;
1288         u64 s_kbytes_written;
1289 
1290         /* the size of zero-out chunk */
1291         unsigned int s_extent_max_zeroout_kb;
1292 
1293         unsigned int s_log_groups_per_flex;
1294         struct flex_groups *s_flex_groups;
1295         ext4_group_t s_flex_groups_allocated;
1296 
1297         /* workqueue for dio unwritten */
1298         struct workqueue_struct *dio_unwritten_wq;
1299 
1300         /* timer for periodic error stats printing */
1301         struct timer_list s_err_report;
1302 
1303         /* Lazy inode table initialization info */
1304         struct ext4_li_request *s_li_request;
1305         /* Wait multiplier for lazy initialization thread */
1306         unsigned int s_li_wait_mult;
1307 
1308         /* Kernel thread for multiple mount protection */
1309         struct task_struct *s_mmp_tsk;
1310 
1311         /* record the last minlen when FITRIM is called. */
1312         atomic_t s_last_trim_minblks;
1313 
1314         /* Reference to checksum algorithm driver via cryptoapi */
1315         struct crypto_shash *s_chksum_driver;
1316 
1317         /* Precomputed FS UUID checksum for seeding other checksums */
1318         __u32 s_csum_seed;
1319 };
1320 
1321 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1322 {
1323         return sb->s_fs_info;
1324 }
1325 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1326 {
1327         return container_of(inode, struct ext4_inode_info, vfs_inode);
1328 }
1329 
1330 static inline struct timespec ext4_current_time(struct inode *inode)
1331 {
1332         return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1333                 current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1334 }
1335 
1336 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1337 {
1338         return ino == EXT4_ROOT_INO ||
1339                 ino == EXT4_USR_QUOTA_INO ||
1340                 ino == EXT4_GRP_QUOTA_INO ||
1341                 ino == EXT4_JOURNAL_INO ||
1342                 ino == EXT4_RESIZE_INO ||
1343                 (ino >= EXT4_FIRST_INO(sb) &&
1344                  ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1345 }
1346 
1347 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
1348                                               struct ext4_io_end *io_end)
1349 {
1350         if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
1351                 io_end->flag |= EXT4_IO_END_UNWRITTEN;
1352                 atomic_inc(&EXT4_I(inode)->i_unwritten);
1353         }
1354 }
1355 
1356 static inline ext4_io_end_t *ext4_inode_aio(struct inode *inode)
1357 {
1358         return inode->i_private;
1359 }
1360 
1361 static inline void ext4_inode_aio_set(struct inode *inode, ext4_io_end_t *io)
1362 {
1363         inode->i_private = io;
1364 }
1365 
1366 /*
1367  * Inode dynamic state flags
1368  */
1369 enum {
1370         EXT4_STATE_JDATA,               /* journaled data exists */
1371         EXT4_STATE_NEW,                 /* inode is newly created */
1372         EXT4_STATE_XATTR,               /* has in-inode xattrs */
1373         EXT4_STATE_NO_EXPAND,           /* No space for expansion */
1374         EXT4_STATE_DA_ALLOC_CLOSE,      /* Alloc DA blks on close */
1375         EXT4_STATE_EXT_MIGRATE,         /* Inode is migrating */
1376         EXT4_STATE_DIO_UNWRITTEN,       /* need convert on dio done*/
1377         EXT4_STATE_NEWENTRY,            /* File just added to dir */
1378         EXT4_STATE_DELALLOC_RESERVED,   /* blks already reserved for delalloc */
1379         EXT4_STATE_DIOREAD_LOCK,        /* Disable support for dio read
1380                                            nolocking */
1381         EXT4_STATE_MAY_INLINE_DATA,     /* may have in-inode data */
1382 };
1383 
1384 #define EXT4_INODE_BIT_FNS(name, field, offset)                         \
1385 static inline int ext4_test_inode_##name(struct inode *inode, int bit)  \
1386 {                                                                       \
1387         return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);     \
1388 }                                                                       \
1389 static inline void ext4_set_inode_##name(struct inode *inode, int bit)  \
1390 {                                                                       \
1391         set_bit(bit + (offset), &EXT4_I(inode)->i_##field);             \
1392 }                                                                       \
1393 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1394 {                                                                       \
1395         clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);           \
1396 }
1397 
1398 EXT4_INODE_BIT_FNS(flag, flags, 0)
1399 #if (BITS_PER_LONG < 64)
1400 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1401 
1402 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1403 {
1404         (ei)->i_state_flags = 0;
1405 }
1406 #else
1407 EXT4_INODE_BIT_FNS(state, flags, 32)
1408 
1409 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1410 {
1411         /* We depend on the fact that callers will set i_flags */
1412 }
1413 #endif
1414 #else
1415 /* Assume that user mode programs are passing in an ext4fs superblock, not
1416  * a kernel struct super_block.  This will allow us to call the feature-test
1417  * macros from user land. */
1418 #define EXT4_SB(sb)     (sb)
1419 #endif
1420 
1421 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1422 
1423 /*
1424  * Codes for operating systems
1425  */
1426 #define EXT4_OS_LINUX           0
1427 #define EXT4_OS_HURD            1
1428 #define EXT4_OS_MASIX           2
1429 #define EXT4_OS_FREEBSD         3
1430 #define EXT4_OS_LITES           4
1431 
1432 /*
1433  * Revision levels
1434  */
1435 #define EXT4_GOOD_OLD_REV       0       /* The good old (original) format */
1436 #define EXT4_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
1437 
1438 #define EXT4_CURRENT_REV        EXT4_GOOD_OLD_REV
1439 #define EXT4_MAX_SUPP_REV       EXT4_DYNAMIC_REV
1440 
1441 #define EXT4_GOOD_OLD_INODE_SIZE 128
1442 
1443 /*
1444  * Feature set definitions
1445  */
1446 
1447 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)                        \
1448         ((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1449 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
1450         ((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1451 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)                      \
1452         ((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1453 #define EXT4_SET_COMPAT_FEATURE(sb,mask)                        \
1454         EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1455 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)                     \
1456         EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1457 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)                      \
1458         EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1459 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)                      \
1460         EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1461 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
1462         EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1463 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
1464         EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1465 
1466 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC        0x0001
1467 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES       0x0002
1468 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL         0x0004
1469 #define EXT4_FEATURE_COMPAT_EXT_ATTR            0x0008
1470 #define EXT4_FEATURE_COMPAT_RESIZE_INODE        0x0010
1471 #define EXT4_FEATURE_COMPAT_DIR_INDEX           0x0020
1472 
1473 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
1474 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
1475 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
1476 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1477 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM         0x0010
1478 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK        0x0020
1479 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE      0x0040
1480 #define EXT4_FEATURE_RO_COMPAT_QUOTA            0x0100
1481 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC         0x0200
1482 /*
1483  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1484  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1485  * all other data structures' checksums.  However, the METADATA_CSUM and
1486  * GDT_CSUM bits are mutually exclusive.
1487  */
1488 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM    0x0400
1489 
1490 #define EXT4_FEATURE_INCOMPAT_COMPRESSION       0x0001
1491 #define EXT4_FEATURE_INCOMPAT_FILETYPE          0x0002
1492 #define EXT4_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
1493 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
1494 #define EXT4_FEATURE_INCOMPAT_META_BG           0x0010
1495 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
1496 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
1497 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1498 #define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
1499 #define EXT4_FEATURE_INCOMPAT_EA_INODE          0x0400 /* EA in inode */
1500 #define EXT4_FEATURE_INCOMPAT_DIRDATA           0x1000 /* data in dirent */
1501 #define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM  0x2000 /* use crc32c for bg */
1502 #define EXT4_FEATURE_INCOMPAT_LARGEDIR          0x4000 /* >2GB or 3-lvl htree */
1503 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA       0x8000 /* data in inode */
1504 
1505 #define EXT2_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1506 #define EXT2_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1507                                          EXT4_FEATURE_INCOMPAT_META_BG)
1508 #define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1509                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1510                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1511 
1512 #define EXT3_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1513 #define EXT3_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1514                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1515                                          EXT4_FEATURE_INCOMPAT_META_BG)
1516 #define EXT3_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1517                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1518                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1519 
1520 #define EXT4_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
1521 #define EXT4_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1522                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1523                                          EXT4_FEATURE_INCOMPAT_META_BG| \
1524                                          EXT4_FEATURE_INCOMPAT_EXTENTS| \
1525                                          EXT4_FEATURE_INCOMPAT_64BIT| \
1526                                          EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1527                                          EXT4_FEATURE_INCOMPAT_MMP |    \
1528                                          EXT4_FEATURE_INCOMPAT_INLINE_DATA)
1529 #define EXT4_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1530                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1531                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1532                                          EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1533                                          EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1534                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1535                                          EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1536                                          EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
1537                                          EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
1538                                          EXT4_FEATURE_RO_COMPAT_QUOTA)
1539 
1540 /*
1541  * Default values for user and/or group using reserved blocks
1542  */
1543 #define EXT4_DEF_RESUID         0
1544 #define EXT4_DEF_RESGID         0
1545 
1546 #define EXT4_DEF_INODE_READAHEAD_BLKS   32
1547 
1548 /*
1549  * Default mount options
1550  */
1551 #define EXT4_DEFM_DEBUG         0x0001
1552 #define EXT4_DEFM_BSDGROUPS     0x0002
1553 #define EXT4_DEFM_XATTR_USER    0x0004
1554 #define EXT4_DEFM_ACL           0x0008
1555 #define EXT4_DEFM_UID16         0x0010
1556 #define EXT4_DEFM_JMODE         0x0060
1557 #define EXT4_DEFM_JMODE_DATA    0x0020
1558 #define EXT4_DEFM_JMODE_ORDERED 0x0040
1559 #define EXT4_DEFM_JMODE_WBACK   0x0060
1560 #define EXT4_DEFM_NOBARRIER     0x0100
1561 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1562 #define EXT4_DEFM_DISCARD       0x0400
1563 #define EXT4_DEFM_NODELALLOC    0x0800
1564 
1565 /*
1566  * Default journal batch times
1567  */
1568 #define EXT4_DEF_MIN_BATCH_TIME 0
1569 #define EXT4_DEF_MAX_BATCH_TIME 15000 /* 15ms */
1570 
1571 /*
1572  * Minimum number of groups in a flexgroup before we separate out
1573  * directories into the first block group of a flexgroup
1574  */
1575 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME 4
1576 
1577 /*
1578  * Structure of a directory entry
1579  */
1580 #define EXT4_NAME_LEN 255
1581 
1582 struct ext4_dir_entry {
1583         __le32  inode;                  /* Inode number */
1584         __le16  rec_len;                /* Directory entry length */
1585         __le16  name_len;               /* Name length */
1586         char    name[EXT4_NAME_LEN];    /* File name */
1587 };
1588 
1589 /*
1590  * The new version of the directory entry.  Since EXT4 structures are
1591  * stored in intel byte order, and the name_len field could never be
1592  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1593  * file_type field.
1594  */
1595 struct ext4_dir_entry_2 {
1596         __le32  inode;                  /* Inode number */
1597         __le16  rec_len;                /* Directory entry length */
1598         __u8    name_len;               /* Name length */
1599         __u8    file_type;
1600         char    name[EXT4_NAME_LEN];    /* File name */
1601 };
1602 
1603 /*
1604  * This is a bogus directory entry at the end of each leaf block that
1605  * records checksums.
1606  */
1607 struct ext4_dir_entry_tail {
1608         __le32  det_reserved_zero1;     /* Pretend to be unused */
1609         __le16  det_rec_len;            /* 12 */
1610         __u8    det_reserved_zero2;     /* Zero name length */
1611         __u8    det_reserved_ft;        /* 0xDE, fake file type */
1612         __le32  det_checksum;           /* crc32c(uuid+inum+dirblock) */
1613 };
1614 
1615 #define EXT4_DIRENT_TAIL(block, blocksize) \
1616         ((struct ext4_dir_entry_tail *)(((void *)(block)) + \
1617                                         ((blocksize) - \
1618                                          sizeof(struct ext4_dir_entry_tail))))
1619 
1620 /*
1621  * Ext4 directory file types.  Only the low 3 bits are used.  The
1622  * other bits are reserved for now.
1623  */
1624 #define EXT4_FT_UNKNOWN         0
1625 #define EXT4_FT_REG_FILE        1
1626 #define EXT4_FT_DIR             2
1627 #define EXT4_FT_CHRDEV          3
1628 #define EXT4_FT_BLKDEV          4
1629 #define EXT4_FT_FIFO            5
1630 #define EXT4_FT_SOCK            6
1631 #define EXT4_FT_SYMLINK         7
1632 
1633 #define EXT4_FT_MAX             8
1634 
1635 #define EXT4_FT_DIR_CSUM        0xDE
1636 
1637 /*
1638  * EXT4_DIR_PAD defines the directory entries boundaries
1639  *
1640  * NOTE: It must be a multiple of 4
1641  */
1642 #define EXT4_DIR_PAD                    4
1643 #define EXT4_DIR_ROUND                  (EXT4_DIR_PAD - 1)
1644 #define EXT4_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT4_DIR_ROUND) & \
1645                                          ~EXT4_DIR_ROUND)
1646 #define EXT4_MAX_REC_LEN                ((1<<16)-1)
1647 
1648 /*
1649  * If we ever get support for fs block sizes > page_size, we'll need
1650  * to remove the #if statements in the next two functions...
1651  */
1652 static inline unsigned int
1653 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1654 {
1655         unsigned len = le16_to_cpu(dlen);
1656 
1657 #if (PAGE_CACHE_SIZE >= 65536)
1658         if (len == EXT4_MAX_REC_LEN || len == 0)
1659                 return blocksize;
1660         return (len & 65532) | ((len & 3) << 16);
1661 #else
1662         return len;
1663 #endif
1664 }
1665 
1666 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1667 {
1668         if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1669                 BUG();
1670 #if (PAGE_CACHE_SIZE >= 65536)
1671         if (len < 65536)
1672                 return cpu_to_le16(len);
1673         if (len == blocksize) {
1674                 if (blocksize == 65536)
1675                         return cpu_to_le16(EXT4_MAX_REC_LEN);
1676                 else
1677                         return cpu_to_le16(0);
1678         }
1679         return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1680 #else
1681         return cpu_to_le16(len);
1682 #endif
1683 }
1684 
1685 /*
1686  * Hash Tree Directory indexing
1687  * (c) Daniel Phillips, 2001
1688  */
1689 
1690 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1691                                       EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1692                     ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1693 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1694 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1695 
1696 /* Legal values for the dx_root hash_version field: */
1697 
1698 #define DX_HASH_LEGACY          0
1699 #define DX_HASH_HALF_MD4        1
1700 #define DX_HASH_TEA             2
1701 #define DX_HASH_LEGACY_UNSIGNED 3
1702 #define DX_HASH_HALF_MD4_UNSIGNED       4
1703 #define DX_HASH_TEA_UNSIGNED            5
1704 
1705 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
1706                               const void *address, unsigned int length)
1707 {
1708         struct {
1709                 struct shash_desc shash;
1710                 char ctx[4];
1711         } desc;
1712         int err;
1713 
1714         BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
1715 
1716         desc.shash.tfm = sbi->s_chksum_driver;
1717         desc.shash.flags = 0;
1718         *(u32 *)desc.ctx = crc;
1719 
1720         err = crypto_shash_update(&desc.shash, address, length);
1721         BUG_ON(err);
1722 
1723         return *(u32 *)desc.ctx;
1724 }
1725 
1726 #ifdef __KERNEL__
1727 
1728 /* hash info structure used by the directory hash */
1729 struct dx_hash_info
1730 {
1731         u32             hash;
1732         u32             minor_hash;
1733         int             hash_version;
1734         u32             *seed;
1735 };
1736 
1737 
1738 /* 32 and 64 bit signed EOF for dx directories */
1739 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
1740 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
1741 
1742 
1743 /*
1744  * Control parameters used by ext4_htree_next_block
1745  */
1746 #define HASH_NB_ALWAYS          1
1747 
1748 
1749 /*
1750  * Describe an inode's exact location on disk and in memory
1751  */
1752 struct ext4_iloc
1753 {
1754         struct buffer_head *bh;
1755         unsigned long offset;
1756         ext4_group_t block_group;
1757 };
1758 
1759 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1760 {
1761         return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1762 }
1763 
1764 /*
1765  * This structure is stuffed into the struct file's private_data field
1766  * for directories.  It is where we put information so that we can do
1767  * readdir operations in hash tree order.
1768  */
1769 struct dir_private_info {
1770         struct rb_root  root;
1771         struct rb_node  *curr_node;
1772         struct fname    *extra_fname;
1773         loff_t          last_pos;
1774         __u32           curr_hash;
1775         __u32           curr_minor_hash;
1776         __u32           next_hash;
1777 };
1778 
1779 /* calculate the first block number of the group */
1780 static inline ext4_fsblk_t
1781 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1782 {
1783         return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1784                 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1785 }
1786 
1787 /*
1788  * Special error return code only used by dx_probe() and its callers.
1789  */
1790 #define ERR_BAD_DX_DIR  -75000
1791 
1792 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1793                         ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1794 
1795 /*
1796  * Timeout and state flag for lazy initialization inode thread.
1797  */
1798 #define EXT4_DEF_LI_WAIT_MULT                   10
1799 #define EXT4_DEF_LI_MAX_START_DELAY             5
1800 #define EXT4_LAZYINIT_QUIT                      0x0001
1801 #define EXT4_LAZYINIT_RUNNING                   0x0002
1802 
1803 /*
1804  * Lazy inode table initialization info
1805  */
1806 struct ext4_lazy_init {
1807         unsigned long           li_state;
1808         struct list_head        li_request_list;
1809         struct mutex            li_list_mtx;
1810 };
1811 
1812 struct ext4_li_request {
1813         struct super_block      *lr_super;
1814         struct ext4_sb_info     *lr_sbi;
1815         ext4_group_t            lr_next_group;
1816         struct list_head        lr_request;
1817         unsigned long           lr_next_sched;
1818         unsigned long           lr_timeout;
1819 };
1820 
1821 struct ext4_features {
1822         struct kobject f_kobj;
1823         struct completion f_kobj_unregister;
1824 };
1825 
1826 /*
1827  * This structure will be used for multiple mount protection. It will be
1828  * written into the block number saved in the s_mmp_block field in the
1829  * superblock. Programs that check MMP should assume that if
1830  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
1831  * to use the filesystem, regardless of how old the timestamp is.
1832  */
1833 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
1834 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
1835 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
1836 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
1837 
1838 struct mmp_struct {
1839         __le32  mmp_magic;              /* Magic number for MMP */
1840         __le32  mmp_seq;                /* Sequence no. updated periodically */
1841 
1842         /*
1843          * mmp_time, mmp_nodename & mmp_bdevname are only used for information
1844          * purposes and do not affect the correctness of the algorithm
1845          */
1846         __le64  mmp_time;               /* Time last updated */
1847         char    mmp_nodename[64];       /* Node which last updated MMP block */
1848         char    mmp_bdevname[32];       /* Bdev which last updated MMP block */
1849 
1850         /*
1851          * mmp_check_interval is used to verify if the MMP block has been
1852          * updated on the block device. The value is updated based on the
1853          * maximum time to write the MMP block during an update cycle.
1854          */
1855         __le16  mmp_check_interval;
1856 
1857         __le16  mmp_pad1;
1858         __le32  mmp_pad2[226];
1859         __le32  mmp_checksum;           /* crc32c(uuid+mmp_block) */
1860 };
1861 
1862 /* arguments passed to the mmp thread */
1863 struct mmpd_data {
1864         struct buffer_head *bh; /* bh from initial read_mmp_block() */
1865         struct super_block *sb;  /* super block of the fs */
1866 };
1867 
1868 /*
1869  * Check interval multiplier
1870  * The MMP block is written every update interval and initially checked every
1871  * update interval x the multiplier (the value is then adapted based on the
1872  * write latency). The reason is that writes can be delayed under load and we
1873  * don't want readers to incorrectly assume that the filesystem is no longer
1874  * in use.
1875  */
1876 #define EXT4_MMP_CHECK_MULT             2UL
1877 
1878 /*
1879  * Minimum interval for MMP checking in seconds.
1880  */
1881 #define EXT4_MMP_MIN_CHECK_INTERVAL     5UL
1882 
1883 /*
1884  * Maximum interval for MMP checking in seconds.
1885  */
1886 #define EXT4_MMP_MAX_CHECK_INTERVAL     300UL
1887 
1888 /*
1889  * Function prototypes
1890  */
1891 
1892 /*
1893  * Ok, these declarations are also in <linux/kernel.h> but none of the
1894  * ext4 source programs needs to include it so they are duplicated here.
1895  */
1896 # define NORET_TYPE     /**/
1897 # define ATTRIB_NORET   __attribute__((noreturn))
1898 # define NORET_AND      noreturn,
1899 
1900 /* bitmap.c */
1901 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
1902 void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1903                                 struct ext4_group_desc *gdp,
1904                                 struct buffer_head *bh, int sz);
1905 int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1906                                   struct ext4_group_desc *gdp,
1907                                   struct buffer_head *bh, int sz);
1908 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1909                                 struct ext4_group_desc *gdp,
1910                                 struct buffer_head *bh);
1911 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1912                                   struct ext4_group_desc *gdp,
1913                                   struct buffer_head *bh);
1914 
1915 /* balloc.c */
1916 extern void ext4_validate_block_bitmap(struct super_block *sb,
1917                                        struct ext4_group_desc *desc,
1918                                        unsigned int block_group,
1919                                        struct buffer_head *bh);
1920 extern unsigned int ext4_block_group(struct super_block *sb,
1921                         ext4_fsblk_t blocknr);
1922 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1923                         ext4_fsblk_t blocknr);
1924 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1925 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1926                         ext4_group_t group);
1927 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1928                                          ext4_fsblk_t goal,
1929                                          unsigned int flags,
1930                                          unsigned long *count,
1931                                          int *errp);
1932 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
1933                                     s64 nclusters, unsigned int flags);
1934 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
1935 extern void ext4_check_blocks_bitmap(struct super_block *);
1936 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1937                                                     ext4_group_t block_group,
1938                                                     struct buffer_head ** bh);
1939 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1940 
1941 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
1942                                                 ext4_group_t block_group);
1943 extern int ext4_wait_block_bitmap(struct super_block *sb,
1944                                   ext4_group_t block_group,
1945                                   struct buffer_head *bh);
1946 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1947                                                   ext4_group_t block_group);
1948 extern void ext4_init_block_bitmap(struct super_block *sb,
1949                                    struct buffer_head *bh,
1950                                    ext4_group_t group,
1951                                    struct ext4_group_desc *desc);
1952 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
1953                                               ext4_group_t block_group,
1954                                               struct ext4_group_desc *gdp);
1955 extern unsigned ext4_num_overhead_clusters(struct super_block *sb,
1956                                            ext4_group_t block_group,
1957                                            struct ext4_group_desc *gdp);
1958 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
1959 
1960 /* dir.c */
1961 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1962                                   struct file *,
1963                                   struct ext4_dir_entry_2 *,
1964                                   struct buffer_head *, char *, int,
1965                                   unsigned int);
1966 #define ext4_check_dir_entry(dir, filp, de, bh, buf, size, offset)      \
1967         unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
1968                                         (de), (bh), (buf), (size), (offset)))
1969 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1970                                     __u32 minor_hash,
1971                                     struct ext4_dir_entry_2 *dirent);
1972 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1973 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1974                              struct buffer_head *bh,
1975                              void *buf, int buf_size,
1976                              const char *name, int namelen,
1977                              struct ext4_dir_entry_2 **dest_de);
1978 void ext4_insert_dentry(struct inode *inode,
1979                         struct ext4_dir_entry_2 *de,
1980                         int buf_size,
1981                         const char *name, int namelen);
1982 static inline void ext4_update_dx_flag(struct inode *inode)
1983 {
1984         if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
1985                                      EXT4_FEATURE_COMPAT_DIR_INDEX))
1986                 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
1987 }
1988 static unsigned char ext4_filetype_table[] = {
1989         DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
1990 };
1991 
1992 static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
1993 {
1994         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) ||
1995             (filetype >= EXT4_FT_MAX))
1996                 return DT_UNKNOWN;
1997 
1998         return ext4_filetype_table[filetype];
1999 }
2000 
2001 /* fsync.c */
2002 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
2003 extern int ext4_flush_unwritten_io(struct inode *);
2004 
2005 /* hash.c */
2006 extern int ext4fs_dirhash(const char *name, int len, struct
2007                           dx_hash_info *hinfo);
2008 
2009 /* ialloc.c */
2010 extern struct inode *ext4_new_inode(handle_t *, struct inode *, umode_t,
2011                                     const struct qstr *qstr, __u32 goal,
2012                                     uid_t *owner);
2013 extern void ext4_free_inode(handle_t *, struct inode *);
2014 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
2015 extern unsigned long ext4_count_free_inodes(struct super_block *);
2016 extern unsigned long ext4_count_dirs(struct super_block *);
2017 extern void ext4_check_inodes_bitmap(struct super_block *);
2018 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
2019 extern int ext4_init_inode_table(struct super_block *sb,
2020                                  ext4_group_t group, int barrier);
2021 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
2022 
2023 /* mballoc.c */
2024 extern long ext4_mb_stats;
2025 extern long ext4_mb_max_to_scan;
2026 extern int ext4_mb_init(struct super_block *);
2027 extern int ext4_mb_release(struct super_block *);
2028 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2029                                 struct ext4_allocation_request *, int *);
2030 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2031 extern void ext4_discard_preallocations(struct inode *);
2032 extern int __init ext4_init_mballoc(void);
2033 extern void ext4_exit_mballoc(void);
2034 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2035                              struct buffer_head *bh, ext4_fsblk_t block,
2036                              unsigned long count, int flags);
2037 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2038                                    ext4_group_t ngroups);
2039 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2040                 ext4_group_t i, struct ext4_group_desc *desc);
2041 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2042                                 ext4_fsblk_t block, unsigned long count);
2043 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2044 
2045 /* inode.c */
2046 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
2047                                                 ext4_lblk_t, int, int *);
2048 struct buffer_head *ext4_bread(handle_t *, struct inode *,
2049                                                 ext4_lblk_t, int, int *);
2050 int ext4_get_block_write(struct inode *inode, sector_t iblock,
2051                          struct buffer_head *bh_result, int create);
2052 int ext4_get_block(struct inode *inode, sector_t iblock,
2053                                 struct buffer_head *bh_result, int create);
2054 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2055                            struct buffer_head *bh, int create);
2056 int ext4_walk_page_buffers(handle_t *handle,
2057                            struct buffer_head *head,
2058                            unsigned from,
2059                            unsigned to,
2060                            int *partial,
2061                            int (*fn)(handle_t *handle,
2062                                      struct buffer_head *bh));
2063 int do_journal_get_write_access(handle_t *handle,
2064                                 struct buffer_head *bh);
2065 #define FALL_BACK_TO_NONDELALLOC 1
2066 #define CONVERT_INLINE_DATA      2
2067 
2068 extern struct inode *ext4_iget(struct super_block *, unsigned long);
2069 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2070 extern int  ext4_setattr(struct dentry *, struct iattr *);
2071 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
2072                                 struct kstat *stat);
2073 extern void ext4_evict_inode(struct inode *);
2074 extern void ext4_clear_inode(struct inode *);
2075 extern int  ext4_sync_inode(handle_t *, struct inode *);
2076 extern void ext4_dirty_inode(struct inode *, int);
2077 extern int ext4_change_inode_journal_flag(struct inode *, int);
2078 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2079 extern int ext4_can_truncate(struct inode *inode);
2080 extern void ext4_truncate(struct inode *);
2081 extern int ext4_punch_hole(struct file *file, loff_t offset, loff_t length);
2082 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
2083 extern void ext4_set_inode_flags(struct inode *);
2084 extern void ext4_get_inode_flags(struct ext4_inode_info *);
2085 extern int ext4_alloc_da_blocks(struct inode *inode);
2086 extern void ext4_set_aops(struct inode *inode);
2087 extern int ext4_writepage_trans_blocks(struct inode *);
2088 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2089 extern int ext4_discard_partial_page_buffers(handle_t *handle,
2090                 struct address_space *mapping, loff_t from,
2091                 loff_t length, int flags);
2092 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
2093 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2094 extern void ext4_da_update_reserve_space(struct inode *inode,
2095                                         int used, int quota_claim);
2096 
2097 /* indirect.c */
2098 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2099                                 struct ext4_map_blocks *map, int flags);
2100 extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
2101                                 const struct iovec *iov, loff_t offset,
2102                                 unsigned long nr_segs);
2103 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
2104 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks, int chunk);
2105 extern void ext4_ind_truncate(struct inode *inode);
2106 
2107 /* ioctl.c */
2108 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2109 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2110 
2111 /* migrate.c */
2112 extern int ext4_ext_migrate(struct inode *);
2113 
2114 /* namei.c */
2115 extern int ext4_dirent_csum_verify(struct inode *inode,
2116                                    struct ext4_dir_entry *dirent);
2117 extern int ext4_orphan_add(handle_t *, struct inode *);
2118 extern int ext4_orphan_del(handle_t *, struct inode *);
2119 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2120                                 __u32 start_minor_hash, __u32 *next_hash);
2121 extern int search_dir(struct buffer_head *bh,
2122                       char *search_buf,
2123                       int buf_size,
2124                       struct inode *dir,
2125                       const struct qstr *d_name,
2126                       unsigned int offset,
2127                       struct ext4_dir_entry_2 **res_dir);
2128 extern int ext4_generic_delete_entry(handle_t *handle,
2129                                      struct inode *dir,
2130                                      struct ext4_dir_entry_2 *de_del,
2131                                      struct buffer_head *bh,
2132                                      void *entry_buf,
2133                                      int buf_size,
2134                                      int csum_size);
2135 
2136 /* resize.c */
2137 extern int ext4_group_add(struct super_block *sb,
2138                                 struct ext4_new_group_data *input);
2139 extern int ext4_group_extend(struct super_block *sb,
2140                                 struct ext4_super_block *es,
2141                                 ext4_fsblk_t n_blocks_count);
2142 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2143 
2144 /* super.c */
2145 extern int ext4_calculate_overhead(struct super_block *sb);
2146 extern int ext4_superblock_csum_verify(struct super_block *sb,
2147                                        struct ext4_super_block *es);
2148 extern void ext4_superblock_csum_set(struct super_block *sb);
2149 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
2150 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
2151 extern void ext4_kvfree(void *ptr);
2152 extern int ext4_alloc_flex_bg_array(struct super_block *sb,
2153                                     ext4_group_t ngroup);
2154 extern __printf(4, 5)
2155 void __ext4_error(struct super_block *, const char *, unsigned int,
2156                   const char *, ...);
2157 #define ext4_error(sb, message...)      __ext4_error(sb, __func__,      \
2158                                                      __LINE__, ## message)
2159 extern __printf(5, 6)
2160 void ext4_error_inode(struct inode *, const char *, unsigned int, ext4_fsblk_t,
2161                       const char *, ...);
2162 extern __printf(5, 6)
2163 void ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
2164                      const char *, ...);
2165 extern void __ext4_std_error(struct super_block *, const char *,
2166                              unsigned int, int);
2167 extern __printf(4, 5)
2168 void __ext4_abort(struct super_block *, const char *, unsigned int,
2169                   const char *, ...);
2170 #define ext4_abort(sb, message...)      __ext4_abort(sb, __func__, \
2171                                                        __LINE__, ## message)
2172 extern __printf(4, 5)
2173 void __ext4_warning(struct super_block *, const char *, unsigned int,
2174                     const char *, ...);
2175 #define ext4_warning(sb, message...)    __ext4_warning(sb, __func__, \
2176                                                        __LINE__, ## message)
2177 extern __printf(3, 4)
2178 void ext4_msg(struct super_block *, const char *, const char *, ...);
2179 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
2180                            const char *, unsigned int, const char *);
2181 #define dump_mmp_msg(sb, mmp, msg)      __dump_mmp_msg(sb, mmp, __func__, \
2182                                                        __LINE__, msg)
2183 extern __printf(7, 8)
2184 void __ext4_grp_locked_error(const char *, unsigned int,
2185                              struct super_block *, ext4_group_t,
2186                              unsigned long, ext4_fsblk_t,
2187                              const char *, ...);
2188 #define ext4_grp_locked_error(sb, grp, message...) \
2189         __ext4_grp_locked_error(__func__, __LINE__, (sb), (grp), ## message)
2190 extern void ext4_update_dynamic_rev(struct super_block *sb);
2191 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
2192                                         __u32 compat);
2193 extern int ext4_update_rocompat_feature(handle_t *handle,
2194                                         struct super_block *sb, __u32 rocompat);
2195 extern int ext4_update_incompat_feature(handle_t *handle,
2196                                         struct super_block *sb, __u32 incompat);
2197 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
2198                                       struct ext4_group_desc *bg);
2199 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
2200                                       struct ext4_group_desc *bg);
2201 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
2202                                      struct ext4_group_desc *bg);
2203 extern __u32 ext4_free_group_clusters(struct super_block *sb,
2204                                       struct ext4_group_desc *bg);
2205 extern __u32 ext4_free_inodes_count(struct super_block *sb,
2206                                  struct ext4_group_desc *bg);
2207 extern __u32 ext4_used_dirs_count(struct super_block *sb,
2208                                 struct ext4_group_desc *bg);
2209 extern __u32 ext4_itable_unused_count(struct super_block *sb,
2210                                    struct ext4_group_desc *bg);
2211 extern void ext4_block_bitmap_set(struct super_block *sb,
2212                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
2213 extern void ext4_inode_bitmap_set(struct super_block *sb,
2214                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
2215 extern void ext4_inode_table_set(struct super_block *sb,
2216                                  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2217 extern void ext4_free_group_clusters_set(struct super_block *sb,
2218                                          struct ext4_group_desc *bg,
2219                                          __u32 count);
2220 extern void ext4_free_inodes_set(struct super_block *sb,
2221                                 struct ext4_group_desc *bg, __u32 count);
2222 extern void ext4_used_dirs_set(struct super_block *sb,
2223                                 struct ext4_group_desc *bg, __u32 count);
2224 extern void ext4_itable_unused_set(struct super_block *sb,
2225                                    struct ext4_group_desc *bg, __u32 count);
2226 extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
2227                                        struct ext4_group_desc *gdp);
2228 extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
2229                                      struct ext4_group_desc *gdp);
2230 
2231 static inline int ext4_has_group_desc_csum(struct super_block *sb)
2232 {
2233         return EXT4_HAS_RO_COMPAT_FEATURE(sb,
2234                                           EXT4_FEATURE_RO_COMPAT_GDT_CSUM |
2235                                           EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
2236 }
2237 
2238 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2239 {
2240         return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2241                 le32_to_cpu(es->s_blocks_count_lo);
2242 }
2243 
2244 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2245 {
2246         return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2247                 le32_to_cpu(es->s_r_blocks_count_lo);
2248 }
2249 
2250 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2251 {
2252         return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2253                 le32_to_cpu(es->s_free_blocks_count_lo);
2254 }
2255 
2256 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2257                                          ext4_fsblk_t blk)
2258 {
2259         es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2260         es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2261 }
2262 
2263 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2264                                               ext4_fsblk_t blk)
2265 {
2266         es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2267         es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2268 }
2269 
2270 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2271                                            ext4_fsblk_t blk)
2272 {
2273         es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2274         es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2275 }
2276 
2277 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
2278 {
2279         if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2280                 return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2281                         le32_to_cpu(raw_inode->i_size_lo);
2282         else
2283                 return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2284 }
2285 
2286 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2287 {
2288         raw_inode->i_size_lo = cpu_to_le32(i_size);
2289         raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2290 }
2291 
2292 static inline
2293 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2294                                             ext4_group_t group)
2295 {
2296          struct ext4_group_info ***grp_info;
2297          long indexv, indexh;
2298          grp_info = EXT4_SB(sb)->s_group_info;
2299          indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2300          indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2301          return grp_info[indexv][indexh];
2302 }
2303 
2304 /*
2305  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2306  * the locking protocol documented in the comments of ext4_group_add()
2307  * in resize.c
2308  */
2309 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2310 {
2311         ext4_group_t    ngroups = EXT4_SB(sb)->s_groups_count;
2312 
2313         smp_rmb();
2314         return ngroups;
2315 }
2316 
2317 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2318                                              ext4_group_t block_group)
2319 {
2320         return block_group >> sbi->s_log_groups_per_flex;
2321 }
2322 
2323 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2324 {
2325         return 1 << sbi->s_log_groups_per_flex;
2326 }
2327 
2328 #define ext4_std_error(sb, errno)                               \
2329 do {                                                            \
2330         if ((errno))                                            \
2331                 __ext4_std_error((sb), __func__, __LINE__, (errno));    \
2332 } while (0)
2333 
2334 #ifdef CONFIG_SMP
2335 /* Each CPU can accumulate percpu_counter_batch clusters in their local
2336  * counters. So we need to make sure we have free clusters more
2337  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2338  */
2339 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2340 #else
2341 #define EXT4_FREECLUSTERS_WATERMARK 0
2342 #endif
2343 
2344 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2345 {
2346         /*
2347          * XXX: replace with spinlock if seen contended -bzzz
2348          */
2349         down_write(&EXT4_I(inode)->i_data_sem);
2350         if (newsize > EXT4_I(inode)->i_disksize)
2351                 EXT4_I(inode)->i_disksize = newsize;
2352         up_write(&EXT4_I(inode)->i_data_sem);
2353         return ;
2354 }
2355 
2356 struct ext4_group_info {
2357         unsigned long   bb_state;
2358         struct rb_root  bb_free_root;
2359         ext4_grpblk_t   bb_first_free;  /* first free block */
2360         ext4_grpblk_t   bb_free;        /* total free blocks */
2361         ext4_grpblk_t   bb_fragments;   /* nr of freespace fragments */
2362         ext4_grpblk_t   bb_largest_free_order;/* order of largest frag in BG */
2363         struct          list_head bb_prealloc_list;
2364 #ifdef DOUBLE_CHECK
2365         void            *bb_bitmap;
2366 #endif
2367         struct rw_semaphore alloc_sem;
2368         ext4_grpblk_t   bb_counters[];  /* Nr of free power-of-two-block
2369                                          * regions, index is order.
2370                                          * bb_counters[3] = 5 means
2371                                          * 5 free 8-block regions. */
2372 };
2373 
2374 #define EXT4_GROUP_INFO_NEED_INIT_BIT           0
2375 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT         1
2376 
2377 #define EXT4_MB_GRP_NEED_INIT(grp)      \
2378         (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2379 
2380 #define EXT4_MB_GRP_WAS_TRIMMED(grp)    \
2381         (test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2382 #define EXT4_MB_GRP_SET_TRIMMED(grp)    \
2383         (set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2384 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)  \
2385         (clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2386 
2387 #define EXT4_MAX_CONTENTION             8
2388 #define EXT4_CONTENTION_THRESHOLD       2
2389 
2390 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2391                                               ext4_group_t group)
2392 {
2393         return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2394 }
2395 
2396 /*
2397  * Returns true if the filesystem is busy enough that attempts to
2398  * access the block group locks has run into contention.
2399  */
2400 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2401 {
2402         return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2403 }
2404 
2405 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2406 {
2407         spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2408         if (spin_trylock(lock))
2409                 /*
2410                  * We're able to grab the lock right away, so drop the
2411                  * lock contention counter.
2412                  */
2413                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2414         else {
2415                 /*
2416                  * The lock is busy, so bump the contention counter,
2417                  * and then wait on the spin lock.
2418                  */
2419                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2420                                   EXT4_MAX_CONTENTION);
2421                 spin_lock(lock);
2422         }
2423 }
2424 
2425 static inline void ext4_unlock_group(struct super_block *sb,
2426                                         ext4_group_t group)
2427 {
2428         spin_unlock(ext4_group_lock_ptr(sb, group));
2429 }
2430 
2431 /*
2432  * Block validity checking
2433  */
2434 #define ext4_check_indirect_blockref(inode, bh)                         \
2435         ext4_check_blockref(__func__, __LINE__, inode,                  \
2436                             (__le32 *)(bh)->b_data,                     \
2437                             EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2438 
2439 #define ext4_ind_check_inode(inode)                                     \
2440         ext4_check_blockref(__func__, __LINE__, inode,                  \
2441                             EXT4_I(inode)->i_data,                      \
2442                             EXT4_NDIR_BLOCKS)
2443 
2444 /*
2445  * Inodes and files operations
2446  */
2447 
2448 /* dir.c */
2449 extern const struct file_operations ext4_dir_operations;
2450 
2451 /* file.c */
2452 extern const struct inode_operations ext4_file_inode_operations;
2453 extern const struct file_operations ext4_file_operations;
2454 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2455 extern void ext4_unwritten_wait(struct inode *inode);
2456 
2457 /* namei.c */
2458 extern const struct inode_operations ext4_dir_inode_operations;
2459 extern const struct inode_operations ext4_special_inode_operations;
2460 extern struct dentry *ext4_get_parent(struct dentry *child);
2461 extern struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2462                                  struct ext4_dir_entry_2 *de,
2463                                  int blocksize, int csum_size,
2464                                  unsigned int parent_ino, int dotdot_real_len);
2465 extern void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
2466                                    unsigned int blocksize);
2467 extern int ext4_handle_dirty_dirent_node(handle_t *handle,
2468                                          struct inode *inode,
2469                                          struct buffer_head *bh);
2470 
2471 /* symlink.c */
2472 extern const struct inode_operations ext4_symlink_inode_operations;
2473 extern const struct inode_operations ext4_fast_symlink_inode_operations;
2474 
2475 /* block_validity */
2476 extern void ext4_release_system_zone(struct super_block *sb);
2477 extern int ext4_setup_system_zone(struct super_block *sb);
2478 extern int __init ext4_init_system_zone(void);
2479 extern void ext4_exit_system_zone(void);
2480 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
2481                                  ext4_fsblk_t start_blk,
2482                                  unsigned int count);
2483 extern int ext4_check_blockref(const char *, unsigned int,
2484                                struct inode *, __le32 *, unsigned int);
2485 
2486 /* extents.c */
2487 struct ext4_ext_path;
2488 struct ext4_extent;
2489 
2490 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
2491 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
2492 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
2493                                        int chunk);
2494 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
2495                                struct ext4_map_blocks *map, int flags);
2496 extern void ext4_ext_truncate(struct inode *);
2497 extern int ext4_ext_punch_hole(struct file *file, loff_t offset,
2498                                 loff_t length);
2499 extern void ext4_ext_init(struct super_block *);
2500 extern void ext4_ext_release(struct super_block *);
2501 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
2502                           loff_t len);
2503 extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
2504                           ssize_t len);
2505 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
2506                            struct ext4_map_blocks *map, int flags);
2507 extern int ext4_ext_calc_metadata_amount(struct inode *inode,
2508                                          ext4_lblk_t lblocks);
2509 extern int ext4_extent_tree_init(handle_t *, struct inode *);
2510 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
2511                                                    int num,
2512                                                    struct ext4_ext_path *path);
2513 extern int ext4_can_extents_be_merged(struct inode *inode,
2514                                       struct ext4_extent *ex1,
2515                                       struct ext4_extent *ex2);
2516 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
2517                                   struct ext4_ext_path *,
2518                                   struct ext4_extent *, int);
2519 extern struct ext4_ext_path *ext4_ext_find_extent(struct inode *, ext4_lblk_t,
2520                                                   struct ext4_ext_path *);
2521 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
2522 extern int ext4_ext_check_inode(struct inode *inode);
2523 extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);
2524 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2525                         __u64 start, __u64 len);
2526 
2527 
2528 /* move_extent.c */
2529 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2530                              __u64 start_orig, __u64 start_donor,
2531                              __u64 len, __u64 *moved_len);
2532 
2533 /* page-io.c */
2534 extern int __init ext4_init_pageio(void);
2535 extern void ext4_add_complete_io(ext4_io_end_t *io_end);
2536 extern void ext4_exit_pageio(void);
2537 extern void ext4_ioend_wait(struct inode *);
2538 extern void ext4_free_io_end(ext4_io_end_t *io);
2539 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
2540 extern void ext4_io_submit(struct ext4_io_submit *io);
2541 extern int ext4_bio_write_page(struct ext4_io_submit *io,
2542                                struct page *page,
2543                                int len,
2544                                struct writeback_control *wbc);
2545 
2546 /* mmp.c */
2547 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
2548 extern void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp);
2549 extern int ext4_mmp_csum_verify(struct super_block *sb,
2550                                 struct mmp_struct *mmp);
2551 
2552 /* BH_Uninit flag: blocks are allocated but uninitialized on disk */
2553 enum ext4_state_bits {
2554         BH_Uninit       /* blocks are allocated but uninitialized on disk */
2555           = BH_JBDPrivateStart,
2556         BH_AllocFromCluster,    /* allocated blocks were part of already
2557                                  * allocated cluster. Note that this flag will
2558                                  * never, ever appear in a buffer_head's state
2559                                  * flag. See EXT4_MAP_FROM_CLUSTER to see where
2560                                  * this is used. */
2561 };
2562 
2563 BUFFER_FNS(Uninit, uninit)
2564 TAS_BUFFER_FNS(Uninit, uninit)
2565 
2566 /*
2567  * Add new method to test whether block and inode bitmaps are properly
2568  * initialized. With uninit_bg reading the block from disk is not enough
2569  * to mark the bitmap uptodate. We need to also zero-out the bitmap
2570  */
2571 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2572 
2573 static inline int bitmap_uptodate(struct buffer_head *bh)
2574 {
2575         return (buffer_uptodate(bh) &&
2576                         test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2577 }
2578 static inline void set_bitmap_uptodate(struct buffer_head *bh)
2579 {
2580         set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2581 }
2582 
2583 /*
2584  * Disable DIO read nolock optimization, so new dioreaders will be forced
2585  * to grab i_mutex
2586  */
2587 static inline void ext4_inode_block_unlocked_dio(struct inode *inode)
2588 {
2589         ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2590         smp_mb();
2591 }
2592 static inline void ext4_inode_resume_unlocked_dio(struct inode *inode)
2593 {
2594         smp_mb();
2595         ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2596 }
2597 
2598 #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
2599 
2600 /* For ioend & aio unwritten conversion wait queues */
2601 #define EXT4_WQ_HASH_SZ         37
2602 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
2603                                             EXT4_WQ_HASH_SZ])
2604 #define ext4_aio_mutex(v)  (&ext4__aio_mutex[((unsigned long)(v)) %\
2605                                              EXT4_WQ_HASH_SZ])
2606 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
2607 extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
2608 
2609 #define EXT4_RESIZING   0
2610 extern int ext4_resize_begin(struct super_block *sb);
2611 extern void ext4_resize_end(struct super_block *sb);
2612 
2613 #endif  /* __KERNEL__ */
2614 
2615 #endif  /* _EXT4_H */
2616 

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